Apache Software Foundation Tomcat vulnerabilities

CVE-2026-24733 Low · 3.7 CWE-20 Feb 17, 2026

Apache Tomcat: Security constraint bypass with HTTP/0.9

Improper Input Validation vulnerability in Apache Tomcat. Tomcat did not limit HTTP/0.9 requests to the GET method. If a security constraint was configured to allow HEAD requests to a URI but deny GET requests, the user could bypass that constraint on GET requests by sending a (specification invalid) HEAD request using HTTP/0.9. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.14, from 10.1.0-M1 through 10.1.49, from 9.0.0.M1 through 9.0.112. Older, EOL versions are also affected. Users are recommended to upgrade to version 11.0.15 or later, 10.1.50 or later or 9.0.113 or later, which fixes the issue.

CVE-2025-66614 Critical · 9.1 CWE-295 Feb 17, 2026

Apache Tomcat: Client certificate verification bypass due to virtual host mapping

Improper Input Validation vulnerability. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.14, from 10.1.0-M1 through 10.1.49, from 9.0.0-M1 through 9.0.112. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.0 through 8.5.100. Older EOL versions are not affected. Tomcat did not validate that the host name provided via the SNI extension was the same as the host name provided in the HTTP host header field. If Tomcat was configured with more than one virtual host and the TLS configuration for one of those hosts did not require client certificate authentication but another one did, it was possible for a client to bypass the client certificate authentication by sending different host names in the SNI extension and the HTTP host header field. The vulnerability only applies if client certificate authentication is only enforced at the Connector. It does not apply if client certificate authentication is enforced at the web application. Users are recommended to upgrade to version 11.0.15 or later, 10.1.50 or later or 9.0.113 or later, which fix the issue.

CVE-2025-61795 Medium · 5.3 CWE-404 Oct 27, 2025

Apache Tomcat: Delayed cleaning of multi-part upload temporary files may lead to DoS

Improper Resource Shutdown or Release vulnerability in Apache Tomcat. If an error occurred (including exceeding limits) during the processing of a multipart upload, temporary copies of the uploaded parts written to disc were not cleaned up immediately but left for the garbage collection process to delete. Depending on JVM settings, application memory usage and application load, it was possible that space for the temporary copies of uploaded parts would be filled faster than GC cleared it, leading to a DoS. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.11, from 10.1.0-M1 through 10.1.46, from 9.0.0.M1 through 9.0.109. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.0 though 8.5.100. Other, older, EOL versions may also be affected. Users are recommended to upgrade to version 11.0.12 or later, 10.1.47 or later or 9.0.110 or later which fixes the issue.

CVE-2025-55754 Critical · 9.6 CWE-150 Oct 27, 2025

Apache Tomcat: console manipulation via escape sequences in log messages

Improper Neutralization of Escape, Meta, or Control Sequences vulnerability in Apache Tomcat. Tomcat did not escape ANSI escape sequences in log messages. If Tomcat was running in a console on a Windows operating system, and the console supported ANSI escape sequences, it was possible for an attacker to use a specially crafted URL to inject ANSI escape sequences to manipulate the console and the clipboard and attempt to trick an administrator into running an attacker controlled command. While no attack vector was found, it may have been possible to mount this attack on other operating systems. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.10, from 10.1.0-M1 through 10.1.44, from 9.0.40 through 9.0.108. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.60 though 8.5.100. Other, older, EOL versions may also be affected. Users are recommended to upgrade to version 11.0.11 or later, 10.1.45 or later or 9.0.109 or later, which fix the issue.

CVE-2025-55752 High · 7.5 CWE-23 Oct 27, 2025

Apache Tomcat: Directory traversal via rewrite with possible RCE if PUT is enabled

Relative Path Traversal vulnerability in Apache Tomcat. The fix for bug 60013 introduced a regression where the rewritten URL was normalized before it was decoded. This introduced the possibility that, for rewrite rules that rewrite query parameters to the URL, an attacker could manipulate the request URI to bypass security constraints including the protection for /WEB-INF/ and /META-INF/. If PUT requests were also enabled then malicious files could be uploaded leading to remote code execution. PUT requests are normally limited to trusted users and it is considered unlikely that PUT requests would be enabled in conjunction with a rewrite that manipulated the URI. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.10, from 10.1.0-M1 through 10.1.44, from 9.0.0.M11 through 9.0.108. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.6 though 8.5.100. Other, older, EOL versions may also be affected. Users are recommended to upgrade to version 11.0.11 or later, 10.1.45 or later or 9.0.109 or later, which fix the issue.

CVE-2025-24813 Critical · 9.8 KEV Urgent · 80 Public exploit CWE-502 Mar 10, 2025

Apache Tomcat Path Equivalence Vulnerability

Path Equivalence: 'file.Name' (Internal Dot) leading to Remote Code Execution and/or Information disclosure and/or malicious content added to uploaded files via write enabled Default Servlet in Apache Tomcat. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.2, from 10.1.0-M1 through 10.1.34, from 9.0.0.M1 through 9.0.98. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.0 though 8.5.100. Other, older, EOL versions may also be affected. If all of the following were true, a malicious user was able to view security sensitive files and/or inject content into those files: - writes enabled for the default servlet (disabled by default) - support for partial PUT (enabled by default) - a target URL for security sensitive uploads that was a sub-directory of a target URL for public uploads - attacker knowledge of the names of security sensitive files being uploaded - the security sensitive files also being uploaded via partial PUT If all of the following were true, a malicious user was able to perform remote code execution: - writes enabled for the default servlet (disabled by default) - support for partial PUT (enabled by default) - application was using Tomcat's file based session persistence with the default storage location - application included a library that may be leveraged in a deserialization attack Users are recommended to upgrade to version 11.0.3, 10.1.35 or 9.0.99, which fixes the issue.

CVE-2023-42794 Medium · 5.9 CWE-459 Oct 10, 2023

Apache Tomcat: FileUpload: DoS due to accumulation of temporary files on Windows

Incomplete Cleanup vulnerability in Apache Tomcat. The internal fork of Commons FileUpload packaged with Apache Tomcat 9.0.70 through 9.0.80 and 8.5.85 through 8.5.93 included an unreleased, in progress refactoring that exposed a potential denial of service on Windows if a web application opened a stream for an uploaded file but failed to close the stream. The file would never be deleted from disk creating the possibility of an eventual denial of service due to the disk being full. Other, EOL versions may also be affected. Users are recommended to upgrade to version 9.0.81 onwards or 8.5.94 onwards, which fixes the issue.

CVE-2023-44487 High · 7.5 KEV Urgent · 73 Public exploit CWE-400 Oct 10, 2023

HTTP/2 Rapid Reset Attack Vulnerability

The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.

CVE-2023-24998 High · 7.5 CWE-770 Feb 20, 2023

Apache Commons FileUpload, Apache Tomcat: FileUpload DoS with excessive parts

Apache Commons FileUpload before 1.5 does not limit the number of request parts to be processed resulting in the possibility of an attacker triggering a DoS with a malicious upload or series of uploads. Note that, like all of the file upload limits, the new configuration option (FileUploadBase#setFileCountMax) is not enabled by default and must be explicitly configured.

CVE-2022-34305 Medium · 6.1 Public exploit CWE-79 Jun 23, 2022

XSS in examples web application

In Apache Tomcat 10.1.0-M1 to 10.1.0-M16, 10.0.0-M1 to 10.0.22, 9.0.30 to 9.0.64 and 8.5.50 to 8.5.81 the Form authentication example in the examples web application displayed user provided data without filtering, exposing a XSS vulnerability.

CVE-2022-25762 High · 8.6 CWE-404 May 13, 2022

Response mix-up with WebSocket concurrent send and close

If a web application sends a WebSocket message concurrently with the WebSocket connection closing when running on Apache Tomcat 8.5.0 to 8.5.75 or Apache Tomcat 9.0.0.M1 to 9.0.20, it is possible that the application will continue to use the socket after it has been closed. The error handling triggered in this case could cause the a pooled object to be placed in the pool twice. This could result in subsequent connections using the same object concurrently which could result in data being returned to the wrong use and/or other errors.

CVE-2022-29885 High · 7.5 Public exploit CWE-400 May 12, 2022

EncryptInterceptor does not provide complete protection on insecure networks

The documentation of Apache Tomcat 10.1.0-M1 to 10.1.0-M14, 10.0.0-M1 to 10.0.20, 9.0.13 to 9.0.62 and 8.5.38 to 8.5.78 for the EncryptInterceptor incorrectly stated it enabled Tomcat clustering to run over an untrusted network. This was not correct. While the EncryptInterceptor does provide confidentiality and integrity protection, it does not protect against all risks associated with running over any untrusted network, particularly DoS risks.

CVE-2021-41079 High · 7.5 CWE-835 Sep 16, 2021

Apache Tomcat DoS with unexpected TLS packet

Apache Tomcat 8.5.0 to 8.5.63, 9.0.0-M1 to 9.0.43 and 10.0.0-M1 to 10.0.2 did not properly validate incoming TLS packets. When Tomcat was configured to use NIO+OpenSSL or NIO2+OpenSSL for TLS, a specially crafted packet could be used to trigger an infinite loop resulting in a denial of service.

CVE-2021-33037 Medium · 5.3 CWE-444 Jul 12, 2021

Incorrect Transfer-Encoding handling with HTTP/1.0

Apache Tomcat 10.0.0-M1 to 10.0.6, 9.0.0.M1 to 9.0.46 and 8.5.0 to 8.5.66 did not correctly parse the HTTP transfer-encoding request header in some circumstances leading to the possibility to request smuggling when used with a reverse proxy. Specifically: - Tomcat incorrectly ignored the transfer encoding header if the client declared it would only accept an HTTP/1.0 response; - Tomcat honoured the identify encoding; and - Tomcat did not ensure that, if present, the chunked encoding was the final encoding.

CVE-2021-30640 Medium · 6.5 CWE-116 Jul 12, 2021

Auth weakness in JNDIRealm

A vulnerability in the JNDI Realm of Apache Tomcat allows an attacker to authenticate using variations of a valid user name and/or to bypass some of the protection provided by the LockOut Realm. This issue affects Apache Tomcat 10.0.0-M1 to 10.0.5; 9.0.0.M1 to 9.0.45; 8.5.0 to 8.5.65.

CVE-2021-25329 High · 7.0 Mar 1, 2021

Incomplete fix for CVE-2020-9484

The fix for CVE-2020-9484 was incomplete. When using Apache Tomcat 10.0.0-M1 to 10.0.0, 9.0.0.M1 to 9.0.41, 8.5.0 to 8.5.61 or 7.0.0. to 7.0.107 with a configuration edge case that was highly unlikely to be used, the Tomcat instance was still vulnerable to CVE-2020-9494. Note that both the previously published prerequisites for CVE-2020-9484 and the previously published mitigations for CVE-2020-9484 also apply to this issue.

CVE-2021-25122 High · 7.5 CWE-200 Mar 1, 2021

Apache Tomcat h2c request mix-up

When responding to new h2c connection requests, Apache Tomcat versions 10.0.0-M1 to 10.0.0, 9.0.0.M1 to 9.0.41 and 8.5.0 to 8.5.61 could duplicate request headers and a limited amount of request body from one request to another meaning user A and user B could both see the results of user A's request.

CVE-2021-24122 Medium · 5.9 CWE-706 Jan 14, 2021

Apache Tomcat information disclosure

When serving resources from a network location using the NTFS file system, Apache Tomcat versions 10.0.0-M1 to 10.0.0-M9, 9.0.0.M1 to 9.0.39, 8.5.0 to 8.5.59 and 7.0.0 to 7.0.106 were susceptible to JSP source code disclosure in some configurations. The root cause was the unexpected behaviour of the JRE API File.getCanonicalPath() which in turn was caused by the inconsistent behaviour of the Windows API (FindFirstFileW) in some circumstances.

CVE-2020-17527 High · 7.5 CWE-200 Dec 3, 2020

Apache Tomcat: Request header mix-up between HTTP/2 streams

While investigating bug 64830 it was discovered that Apache Tomcat 10.0.0-M1 to 10.0.0-M9, 9.0.0-M1 to 9.0.39 and 8.5.0 to 8.5.59 could re-use an HTTP request header value from the previous stream received on an HTTP/2 connection for the request associated with the subsequent stream. While this would most likely lead to an error and the closure of the HTTP/2 connection, it is possible that information could leak between requests.

CVE-2020-13943 Medium · 4.3 Oct 12, 2020

If an HTTP/2 client connecting to Apache Tomcat 10.0.0-M1 to 10.0.0-M7, 9.0.0.M1 to…

If an HTTP/2 client connecting to Apache Tomcat 10.0.0-M1 to 10.0.0-M7, 9.0.0.M1 to 9.0.37 or 8.5.0 to 8.5.57 exceeded the agreed maximum number of concurrent streams for a connection (in violation of the HTTP/2 protocol), it was possible that a subsequent request made on that connection could contain HTTP headers - including HTTP/2 pseudo headers - from a previous request rather than the intended headers. This could lead to users seeing responses for unexpected resources.

CVE-2020-13935 High · 7.5 CWE-835 Jul 14, 2020

Infinite Loop in Apache Software Foundation Tomcat

The payload length in a WebSocket frame was not correctly validated in Apache Tomcat 10.0.0-M1 to 10.0.0-M6, 9.0.0.M1 to 9.0.36, 8.5.0 to 8.5.56 and 7.0.27 to 7.0.104. Invalid payload lengths could trigger an infinite loop. Multiple requests with invalid payload lengths could lead to a denial of service.

CVE-2020-13934 High · 7.5 CWE-401 Jul 14, 2020

Missing Release of Memory after Effective Lifetime in Apache Software Foundation Tomcat

An h2c direct connection to Apache Tomcat 10.0.0-M1 to 10.0.0-M6, 9.0.0.M5 to 9.0.36 and 8.5.1 to 8.5.56 did not release the HTTP/1.1 processor after the upgrade to HTTP/2. If a sufficient number of such requests were made, an OutOfMemoryException could occur leading to a denial of service.

CVE-2020-8022 High · 7.8 CWE-276 Jun 29, 2020

User-writeable configuration file /usr/lib/tmpfiles.d/tomcat.conf allows for escalation of priviliges

A Incorrect Default Permissions vulnerability in the packaging of tomcat on SUSE Enterprise Storage 5, SUSE Linux Enterprise Server 12-SP2-BCL, SUSE Linux Enterprise Server 12-SP2-LTSS, SUSE Linux Enterprise Server 12-SP3-BCL, SUSE Linux Enterprise Server 12-SP3-LTSS, SUSE Linux Enterprise Server 12-SP4, SUSE Linux Enterprise Server 12-SP5, SUSE Linux Enterprise Server 15-LTSS, SUSE Linux Enterprise Server for SAP 12-SP2, SUSE Linux Enterprise Server for SAP 12-SP3, SUSE Linux Enterprise Server for SAP 15, SUSE OpenStack Cloud 7, SUSE OpenStack Cloud 8, SUSE OpenStack Cloud Crowbar 8 allows local attackers to escalate from group tomcat to root. This issue affects: SUSE Enterprise Storage 5 tomcat versions prior to 8.0.53-29.32.1. SUSE Linux Enterprise Server 12-SP2-BCL tomcat versions prior to 8.0.53-29.32.1. SUSE Linux Enterprise Server 12-SP2-LTSS tomcat versions prior to 8.0.53-29.32.1. SUSE Linux Enterprise Server 12-SP3-BCL tomcat versions prior to 8.0.53-29.32.1. SUSE Linux Enterprise Server 12-SP3-LTSS tomcat versions prior to 8.0.53-29.32.1. SUSE Linux Enterprise Server 12-SP4 tomcat versions prior to 9.0.35-3.39.1. SUSE Linux Enterprise Server 12-SP5 tomcat versions prior to 9.0.35-3.39.1. SUSE Linux Enterprise Server 15-LTSS tomcat versions prior to 9.0.35-3.57.3. SUSE Linux Enterprise Server for SAP 12-SP2 tomcat versions prior to 8.0.53-29.32.1. SUSE Linux Enterprise Server for SAP 12-SP3 tomcat versions prior to 8.0.53-29.32.1. SUSE Linux Enterprise Server for SAP 15 tomcat versions prior to 9.0.35-3.57.3. SUSE OpenStack Cloud 7 tomcat versions prior to 8.0.53-29.32.1. SUSE OpenStack Cloud 8 tomcat versions prior to 8.0.53-29.32.1. SUSE OpenStack Cloud Crowbar 8 tomcat versions prior to 8.0.53-29.32.1.

CVE-2020-11996 High · 7.5 Jun 26, 2020

A specially crafted sequence of HTTP/2 requests sent to Apache Tomcat 10.0.0-M1 to…

A specially crafted sequence of HTTP/2 requests sent to Apache Tomcat 10.0.0-M1 to 10.0.0-M5, 9.0.0.M1 to 9.0.35 and 8.5.0 to 8.5.55 could trigger high CPU usage for several seconds. If a sufficient number of such requests were made on concurrent HTTP/2 connections, the server could become unresponsive.

CVE-2020-9484 High · 7.0 Public exploit CWE-502 May 20, 2020

Deserialization of Untrusted Data in Apache Software Foundation Tomcat

When using Apache Tomcat versions 10.0.0-M1 to 10.0.0-M4, 9.0.0.M1 to 9.0.34, 8.5.0 to 8.5.54 and 7.0.0 to 7.0.103 if a) an attacker is able to control the contents and name of a file on the server; and b) the server is configured to use the PersistenceManager with a FileStore; and c) the PersistenceManager is configured with sessionAttributeValueClassNameFilter="null" (the default unless a SecurityManager is used) or a sufficiently lax filter to allow the attacker provided object to be deserialized; and d) the attacker knows the relative file path from the storage location used by FileStore to the file the attacker has control over; then, using a specifically crafted request, the attacker will be able to trigger remote code execution via deserialization of the file under their control. Note that all of conditions a) to d) must be true for the attack to succeed.