Apache Software Foundation vulnerabilities

Published CVEs affecting Apache Software Foundation products: 1272 record(s), with severity, exploitation and fixes.

CVE-2026-76986 Medium · 6.1 CWE-79 Aug 31, 2026

Apache Wicket: XSS in AbstractSingleSelectChoice via getNullValidDisplayValue

Improper neutralization of input during web page generation in Apache Wicket. org.apache.wicket.markup.html.form.AbstractSingleSelectChoice, the base class of DropDownChoice, writes the body of the default option — the entry shown when no choice is selected — into the markup as it is, while every other option body in the same select is escaped according to the escape-model-strings setting. The body comes from getNullValidDisplayValue() or getNullKeyDisplayValue(), both of which are protected, so what they return is not necessarily the plain text the default implementation reads from a resource bundle. An application is affected where it overrides one of those methods and returns a value holding data an attacker can influence, or where its own nullValid or null bundle entry holds such a value. The bundles shipped with Wicket contain plain text. RadioChoice overrides getDefaultChoice to emit no default option and is not affected. As a workaround, escape the value in the override. This issue affects Apache Wicket: from 8.0.0 through 8.18.0, from 9.0.0 through 9.23.0, from 10.0.0 through 10.10.0. Older, unsupported releases from 1.5.0 onwards are also affected. Users are recommended to upgrade to version 8.19.0, 9.24.0 or 10.11.0, which fix the issue.

CVE-2026-76985 Medium · 5.4 CWE-79 Aug 31, 2026

Apache Wicket: XSS in Palette via getAdditionalAttributes

Improper neutralization of input during web page generation in Apache Wicket. org.apache.wicket.extensions.markup.html.form.palette.component.AbstractOptions, which renders the two option lists of a Palette, escapes the id and the display value of each option according to the escape-model-strings setting, and wrote the attribute names and values returned by getAdditionalAttributes into the <option> tag as they came. An application is affected where it overrides Palette.getAdditionalAttributesForChoices, Palette.getAdditionalAttributesForSelection or AbstractOptions.getAdditionalAttributes and returns a value holding data an attacker can influence. These methods return null by default, so an application that does not override them is not affected. As a workaround, escape the values in the override. This issue affects Apache Wicket: from 8.0.0 through 8.18.0, from 9.0.0 through 9.23.0, from 10.0.0 through 10.10.0. Older, unsupported releases from 1.4.0 onwards are also affected. Users are recommended to upgrade to version 8.19.0, 9.24.0 or 10.11.0, which fix the issue.

CVE-2026-76984 Medium · 5.4 CWE-79 Aug 31, 2026

Apache Wicket: XSS in MetaDataHeaderItem via addTagAttribute

Improper neutralization of input during web page generation in Apache Wicket. org.apache.wicket.markup.head.MetaDataHeaderItem generates <meta> and <link> header tags. It escaped the attribute names it wrote, but ran the attribute values through a replacement of " with \". A backslash before a double quote means nothing in HTML, so a value containing a double quote ends its own attribute and what follows is parsed as further attributes of the generated tag. An application is affected where it supplies an attribute value holding data an attacker can influence, through addTagAttribute or the forMetaTag and forLinkTag factory methods. A value may be given as an IModel, so it is not necessarily a literal. There is no setting to change; an application can only avoid supplying a value that contains a double quote. Note that these values have never been escaped effectively: before the change released in 6.24.0, 7.4.0 and 8.0.0 they were written with no escaping at all. This issue affects Apache Wicket: from 8.0.0 through 8.18.0, from 9.0.0 through 9.23.0, from 10.0.0 through 10.10.0. Older, unsupported releases from 6.17.0 onwards are also affected. Users are recommended to upgrade to version 8.19.0, 9.24.0 or 10.11.0, which fix the issue.

CVE-2026-76983 Medium · 5.4 CWE-79 Aug 31, 2026

Apache Wicket: XSS in AutoLabelTextResolver via FormComponent.setLabel

Improper neutralization of input during web page generation in Apache Wicket. The <wicket:label> tag is provided by org.apache.wicket.markup.html.form.AutoLabelTextResolver, which is registered by default in every WebApplication. The resolver writes the label it finds into the markup as it is, and reads no escaping setting at all, so markup in a label is rendered as markup. When the label comes from the labelled component's label model, set through FormComponent#setLabel(IModel), it is written to the markup unescaped. An application is affected where the label of a form component holds data an attacker can influence. Wicket cannot determine where a model value comes from, so whether it reaches the page from a request or from storage is a property of the application. There is no workaround. Unlike every other rendering path in Wicket, the resolver never consulted the escape-model-strings setting, so an application had no way to ask for the label to be escaped. The body of a <wicket:label> tag is markup by design and is not affected; it remains the supported way to place markup in a label. This issue affects Apache Wicket: from 8.0.0 through 8.18.0, from 9.0.0 through 9.23.0, from 10.0.0 through 10.10.0. Older, unsupported releases from 1.5.0 onwards are also affected. Users are recommended to upgrade to version 8.19.0, 9.24.0 or 10.11.0, which fix the issue.

CVE-2026-76982 Medium · 5.4 CWE-79 Aug 31, 2026

Apache Wicket: XSS in Button via its model object

Improper neutralization of input during web page generation in Apache Wicket. org.apache.wicket.markup.html.form.Button clears the escape-model-strings flag in its constructor, so that the value attribute it writes is not encoded twice — ComponentTag already encodes attribute values when it writes the tag. That reasoning holds only for the attribute. When the component is attached to a <button> element rather than an <input>, it writes its model object into the element body instead, and nothing encodes an element body, so markup in the model is rendered as markup. An application is affected where it renders a Button on a <button> element and that button's model holds data an attacker can influence. Wicket cannot determine where a model value comes from, so whether it reaches the page from a request or from storage is a property of the application. The subclasses that inherit this constructor — AjaxButton, AjaxFallbackButton and WizardButton — are affected on the same terms. As a workaround, calling setEscapeModelStrings(true) on a button that renders as a <button> element escapes the body correctly, and does not cause double encoding, because the value attribute is written only for <input> elements. This issue affects Apache Wicket: from 8.0.0 through 8.18.0, from 9.0.0 through 9.23.0, from 10.0.0 through 10.10.0. Older, unsupported releases from 6.25.0 and 7.5.0 onwards are also affected. Users are recommended to upgrade to version 8.19.0, 9.24.0 or 10.11.0, which fix the issue.

CVE-2026-75802 Medium · 5.4 CWE-79 Aug 31, 2026

Apache Wicket: XSS in AjaxEditableLabel and its subclasses via IChoiceRenderer and defaultNullLabel

AjaxEditableChoiceLabel in wicket-extensions, when constructed with a non-null IChoiceRenderer, writes the display value obtained from that renderer into the label's markup without applying the HTML escaping Wicket performs by default for component model values. An attacker who can influence the choice or model data rendered by such a label can inject HTML or script that executes in the browser of any user who views the page. The same value is correctly escaped when the component's dropdown editor renders it as an option, so only the label rendering is affected. AjaxEditableLabel, AjaxEditableChoiceLabel and AjaxEditableMultiLineLabel write the value returned by the protected defaultNullLabel() method into the label's markup the same way when the component's model is empty, while the model value they show otherwise is escaped. The default implementation returns a constant, so an application is affected where it overrides that method and returns a value an attacker can influence. Neither value could be escaped by configuration, because escapeModelStrings had no effect on any of the three components: it is read by the label they render with rather than by the component itself, and nothing carried the setting across. This issue affects Apache Wicket: from 8.0.0 through 8.18.0, from 9.0.0 through 9.23.0, from 10.0.0 through 10.10.0. Older, unsupported releases are also affected; the display value from the renderer since 6.22.0 and the null label since 1.4.0. Users are recommended to upgrade to version 8.19.0, 9.24.0 or 10.11.0, which fix the issue.

CVE-2026-71378 Medium · 4.6 CWE-352 Aug 31, 2026

Apache Wicket: Cross-Site Request Forgery (CSRF) protection bypass in ResourceIsolationRequestCycleListener

ResourceIsolationRequestCycleListener protects a Wicket application against cross-site request forgery by rejecting requests that a resource isolation policy judges to come from another origin. Its default policy, FetchMetadataResourceIsolationPolicy, was derived from a reference implementation written to guard static resources, and it inherited two allowances that are unsafe when the thing being guarded is an action on a page: * Every "simple top-level navigation" was allowed. Any GET request carrying Sec-Fetch-Mode: navigate whose Sec-Fetch-Dest was neither object nor embed was allowed, whatever Sec-Fetch-Site said — including cross-site. Wicket invokes component listeners (Link.onClick(), form submits, behaviour callbacks) through ordinary GET navigations, so a page under an attacker's control could navigate the victim's browser to a listener URL and have that listener run inside the victim's authenticated session. Browsers send SameSite=Lax cookies — the effective default when no SameSite attribute is set — on cross-site top-level GET navigations, so the victim's session cookie accompanied the request. * Sec-Fetch-Site: same-site was allowed unconditionally. That value means the same registrable domain and scheme but a different origin — another subdomain or another port. Any sibling origin could therefore invoke any listener by any method, POST form submits included, and cookies are always sent on same-site requests regardless of SameSite. A hostile sibling origin obtained through a subdomain takeover, through delegated user content, or through an XSS elsewhere on the site could act as the authenticated user. Users are recommended to upgrade to version 9.24.0 or 10.11.0, which fix the issue. Affected versions * Apache Wicket 9.1.0 through 9.23.0 * Apache Wicket 10.0.0 through 10.10.0 Not affected Any release older than 9.1.0: * Apache Wicket 8.x (8.0.0 through 8.17.0). The resource isolation classes do not exist in the 8.x line, which offers only the Origin/Referer-based CsrfPreventionRequestCycleListener. No 8.x release requires a fix. * Apache Wicket 9.0.0. ResourceIsolationRequestCycleListener and FetchMetadataResourceIsolationPolicy were introduced by WICKET-6786 and first shipped in 9.1.0 (released 2020-10-07).

CVE-2026-71257 High · 7.5 CWE-770 Aug 31, 2026

Apache Wicket: Configured file upload limits are not enforced when the multipart request has already been parsed

Apache Wicket enforces the upload limits configured on a form or upload field while parsing a multipart request with Apache Commons FileUpload. If the request body has already been consumed by another component, Commons FileUpload returns no items and Wicket falls back to reading the upload through HttpServletRequest#getParts(). The per-file size limit (for example Form#setFileMaxSize) and the file count limit (Form#setFileCountMax) are not applied to the parts obtained that way, and no exception is raised, so the upload is processed as though those limits had been satisfied. A remote uploader can therefore submit files that are larger, or more numerous, than the application permits, up to whatever the component that parsed the request allows. A part carrying no Content-Type header is additionally read into memory in full during parsing, so the size of that allocation is determined by the request and bounded only by those same external limits. The total upload size limit (Form#setMaxSize) is not affected. Commons FileUpload compares the declared Content-Length against it before reading the body, so a request declaring an oversized length is rejected before the fallback is reached. The fallback is reached in deployments where a servlet or filter has already parsed the request body — for example a servlet annotated with @MultipartConfig, Spring Boot's multipart resolver, or any filter that calls HttpServletRequest#getParameter() on a multipart request. It applies to the Wicket components that accept uploads on that path, including Form with FileUploadField, FileUploadToResourceField and AjaxFileDropBehavior. Applications that configure neither a per-file nor a file-count limit are not affected, as Wicket applies neither by default. This issue affects Apache Wicket: from 8.0.0 through 8.18.0, from 9.0.0 through 9.23.0, from 10.0.0 through 10.10.0. Users are recommended to upgrade to version 8.19.0, 9.24.0 or 10.11.0, which fix the issue. Users of Apache Wicket 7.x or older, which are no longer supported, should upgrade to a supported version. As a workaround, configure equivalent limits in the component that parses the request — for example spring.servlet.multipart.max-file-size and max-request-size, or maxFileSize and maxRequestSize in @MultipartConfig or in the web.xml <multipart-config> element.

CVE-2026-70449 Medium · 5.3 CWE-22 Aug 31, 2026

Apache Wicket: Path traversal in resource style/variation/locale

Improper validation of resource URL attributes in Apache Wicket allows an unauthenticated remote attacker to read files from the web application, including files under WEB-INF that the servlet container would not otherwise serve. The locale, style and variation attributes decoded from a package resource URL are spliced into the resource lookup path without being checked for path separators. The IPackageResourceGuard — whose rejection of .. is one of the two intended controls — is applied to the resource name before those attributes are appended, and WebApplicationPath rejects only paths literally beginning with WEB-INF/. Neither control ever inspects the attacker-controlled portion of the path. On servlet containers that normalize .. in ServletContext.getResource(), a crafted request therefore escapes the intended package directory. The set of readable files is limited to the file extensions permitted by the configured IPackageResourceGuard. The default SecurePackageResourceGuard permits only js, css, png, jpg, jpeg, gif, ico, cur, map, html, txt, swf, bmp, svg, avif, eot, ttf, woff and woff2, which excludes configuration formats. Applications that have added patterns to the guard, or replaced it with the blocklist-based PackageResourceGuard, can additionally disclose configuration files such as web.xml. Independently of the extension, the lookup performed before the guard runs acts as an existence oracle for arbitrary paths. This issue affects Apache Wicket 8.18.0 and before, 9.23.0 and before and 10.10.0 and before. Users are recommended to upgrade to version 8.19.0, 9.24.0 or 10.11.0, which fix the issue. Users of Apache Wicket 7.x or older, which are no longer supported, should upgrade to a supported version.

CVE-2026-58301 Medium · 6.5 CWE-918 Aug 31, 2026

Apache Shiro: Server-side POST request may be steered to an alternate host

When Apache Shiro is used with the Jakarta EE integration module, a low-privileged user can craft an HTTP request that causes the server to initiate a connection to an attacker-controlled URL and transmit attacker-controlled data. This vulnerability affects Apache Shiro versions 2.x through 3.0.0 only in deployments that use the Jakarta EE integration module. Mitigation: Upgrade to version 3.0.1 or later, which fixes the issue. + Alternatively, you can set the `org.apache.shiro.form-resubmit-host` (String) and `org.apache.shiro.form-resubmit-port` (Integer) system properties to restrict the host and port that Shiro will connect to when resubmitting a form.

CVE-2026-75020 High · 8.1 CWE-90 Aug 27, 2026

Apache APISIX: ldap-auth plugin cross-subtree identity impersonation

Improper Neutralization of Special Elements used in an LDAP Query ('LDAP Injection') vulnerability in Apache APISIX. A caller who holds valid credentials for one entry in the LDAP directory can authenticate through APISIX as a consumer mapped to a different entry, one the plugin's configured scope was meant to keep out of reach. This issue affects Apache APISIX: from 2.11.0 through 3.17.0. Users are recommended to upgrade to version 3.18.0, which fixes the issue.

CVE-2026-75005 High · 7.5 CWE-407 Aug 27, 2026

Apache APISIX: Unauthenticated CPU-exhaustion DoS

Inefficient Algorithmic Complexity vulnerability in Apache APISIX. A single small request can pin a gateway worker at 100% CPU for an extended period in graphql-limit-count routes. This issue affects Apache APISIX: 3.17.0. Users are recommended to upgrade to version 3.18.0, which fixes the issue.

CVE-2026-74848 High · 7.5 CWE-444 Aug 27, 2026

Apache APISIX: Cross-user response poisoning in serverless plugins

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in Apache APISIX. An attacker could make other clients receive attacker-chosen or other users' responses on serverless-plugin routes. This issue affects Apache APISIX: from 2.12.0 through 3.17.0. Users are recommended to upgrade to version 3.18.0, which fixes the issue.

CVE-2026-63041 High · 8.8 CWE-807 Aug 26, 2026

Apache APISIX: attach-consumer-label does not strip client-supplied consumer-label headers

Reliance on Untrusted Inputs in a Security Decision vulnerability in Apache APISIX. This vulnerability allows an attacker to escalate privilege or perform an authorization bypass by sending certain values that the attach-consumer-label plugin does not sanitise correctly. This issue affects Apache APISIX: from 3.11.0 through 3.17.0. Users are recommended to upgrade to version 3.18.0, which fixes the issue.

CVE-2026-73180 Medium · 6.8 CWE-613 Aug 25, 2026

Apache Tomcat: Authenticated WebSocket session survives end of HTTP session

Insufficient Session Expiration vulnerability in Apache Tomcat meant that if the session ID for an authenticated HTTP session was changed after a WebSocket connection had been established under that authenticated HTTP session, the WebSokcet session would not be closed as required by the Jakarta WebSocket specification when the HTTP session ended. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.0.M1 through 9.0.120. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100, from 7.0.43 through 7.0.109. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix the issue.

CVE-2026-68763 High · 7.5 CWE-400 Aug 25, 2026

Apache Tomcat: DoS via allocation leak in HTTP/2 backlog tracking when a stream is reset

Uncontrolled Resource Consumption vulnerability in Apache Tomcat via an allocation leak in the HTTP/2 backlog tracking when a stream is reset This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.39 through 9.0.120. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.59 through 8.5.100. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix the issue.

CVE-2026-68569 High · 8.1 CWE-287 Aug 25, 2026

Apache Tomcat: Principal lookup can fail open in some cases

Improper Authentication vulnerability in Apache Tomcat meant that in some circumstances (e.g. CLIENT-CERT, SPNEGO) that a user would be authenticated even if the user did not exist in the DataSourceRealm. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.0.M1 through 9.0.120. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix the issue.

CVE-2026-68525 Critical · 9.1 CWE-863 Aug 25, 2026

Apache Tomcat: Redirect after FORM auth may bypass method specific constraints

Incorrect Authorization vulnerability in Apache Tomcat's FORM authentication process allows the bypassing of a security constraint that limits user has access to a resource POST but not GET. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.0.M1 through 9.0.120. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fixes the issue.

CVE-2026-66422 High · 8.1 CWE-285 Aug 25, 2026

Apache Tomcat: Servlet role references can bypass declarative role constraints

Improper Authorization vulnerability in Apache Tomcat cause by security-role-ref definitions being incorrectly used as role aliases within the Realm in additional to the correct usage with Request.isUserInRole(). This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.25 through 9.0.120. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.46 through 8.5.100, from 7.0.97 through 7.0.109. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix the issue.

CVE-2026-65927 High · 7.5 CWE-193 Aug 25, 2026

Apache Tomcat: RewriteValve [N] restarts at the second rule and may bypass access control

Off-by-one Error vulnerability in Apache Tomcat impacting the [N] flag on the rewrite valves causes rewrite processing to restart at the second rule rather than the first rule. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.0.M1 through 9.0.120. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121 which fix the issue.

CVE-2026-65905 Critical · 9.8 CWE-294 Aug 25, 2026

Apache Tomcat: Limited replay attack possible with DIGEST authentication

Authentication Bypass by Capture-replay vulnerability in Apache Tomcat's DIGEST authenticator. If, before windowSize requests have been made, a client makes a DIGEST authenticated request with a nonceCount on the upper boundary of the replay window then that request is replayable once only while the associated nonceCount remains within the replay window. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.0.M1 through 9.0.120. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100, from 7.0.30 through 7.0.109. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix the issue.

CVE-2026-65637 Critical · 9.8 CWE-20 Aug 25, 2026

Apache Tomcat: HTTP/2 no-authority bypass of strict SNI validation - CVE-2026-32990 fix incomplete

Improper Input Validation vulnerability in Apache Tomcat due to incomplete fix for CVE-2026-32990. This issue affects Apache Tomcat: from 11.0.20 through 11.0.24, from 10.1.53 through 10.1.57, from 9.0.115 through 9.0.120. Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix the issue.

CVE-2026-65183 High · 8.1 CWE-367 Aug 25, 2026

Apache Tomcat: TOCTOU when setting specific permissions for Unix Domain Sockets

Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability in Apache Tomcat when creating unix domain sockets allows an unauthorised local user to access the unix domain socket. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.42 through 9.0.120. Users are recommended to upgrade to version 11.0.25, 10.1.58, 9.0.121, which fixes the issue.

CVE-2026-65182 Critical · 9.1 CWE-284 Aug 25, 2026

Apache Tomcat: Bypass longest prefix security constraint

Improper Access Control, Incorrect Authorization vulnerability in Apache Tomcat leads to security constraint bypass if a constraint for a longer path is specified before a more restrictive constraint for a shorter sub-path. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.0.M1 through 9.0.120, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Users are recommended to upgrade to version 11.0.25, 10.1.58, 9.0.121, which fixes the issue.

CVE-2026-55976 Critical · 9.1 CWE-918 Aug 25, 2026

Apache Hive: SSRF vulnerability in Hive Avro Serde due to Insufficient input validation on avro.schema.url

Server-Side Request Forgery (SSRF) in Avro SerDe schema resolution in Apache Hive before 4.2.1 allows an authenticated remote attacker with CREATE TABLE privilege to cause the Hive server to fetch an attacker-controlled URL when resolving the avro.schema.url table property on an Avro table that is subsequently queried. This can expose cloud instance metadata, internal network services, or local server files to the Hive process identity. Users are recommended to upgrade to version 4.2.1, which fixes this issue. Attacker access requirements: * Network access to HiveServer2 / Metastore: required (remote attacker model). * Valid Hive authentication: required. * CREATE TABLE (or equivalent) privilege: required, so the attacker can set avro.schema.url in table properties. * SELECT privilege on the malicious table: not required for the creator, who can typically query their own table; any other user granted SELECT can also trigger the fetch. * Write access to the table LOCATION: not required; the attack uses the schema URL, not the data path. * Admin / superuser privileges: not required; an ordinary authenticated user with DDL rights is sufficient. * External tables enabled: typically required in practice, and enabled by default in most deployments. Detection guidance: * Inspect metastore / Hive table metadata for Avro tables whose avro.schema.url uses unexpected schemes such as http, https, file, or ftp, or points at link-local / cloud metadata addresses (for example 169.254.169.254) or other internal hosts. * Review HiveServer2 and Metastore logs around CREATE/ALTER TABLE and queries against Avro tables for schema-resolution failures or outbound fetches of avro.schema.url. * Correlate CREATE TABLE / ALTER TABLE activity that sets avro.schema.url with subsequent SELECT activity on the same table, especially when the URL target is unusual for schema distribution. * On cloud deployments, check instance / VPC flow logs and metadata service access logs for unexpected requests from Hive host identities shortly after Avro DDL or query activity.