Vulnerabilidades do Apache Software Foundation Cxf

In Apache CXF, STSTokenValidator checks whether a SAML assertion is signed by a trusted certificate before deciding to send it to the STS. That result was stored in one object shared by all requests, so one request could read another's result. A remote, unauthenticated attacker could send a forged assertion signed with an untrusted certificate while legitimate requests were being processed, and it could be accepted as trusted without ever reaching the STS. Only services that use STSTokenValidator to validate SAML tokens without alwaysValidateToSts set are affected.  Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.

Apache CXF's FIQL query parser has a vulnerability in how it searches for operators in query expressions. The search pattern can get stuck trying many combinations when it encounters a long string without an operator, causing the parser to consume excessive CPU time. An attacker can send a crafted query to make the server use up CPU resources, potentially slowing down or stopping other requests. The fix was to limit FIQL expressions to 4 KiB by default, preventing attackers from sending extremely long inputs while still allowing normal queries. Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.

CompressionUtils.inflate() decompressed attacker-controlled DEFLATE data with no output-size cap. A small (~KB) crafted payload could expand to gigabytes on the heap. Reachable via JWE decryption when zip=DEF (e.g. JoseSessionTokenProvider with RSA-OAEP key wrap) and via SAML redirect/POST binding token inflation — in both cases decompression happens before/independent of trust validation. Fix: Added a configurable maximum inflated-size cap (default 10 MiB, org.apache.cxf.compression-max-inflated-size system property) to CompressionUtils.inflate(); aborts with DataFormatException once exceeded. Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.

Improper enforcement of single-use authorization code semantics in the JPA OAuth2 authorization code grant provider in Apache CXFallows a remote attacker to obtain multiple valid access tokens from a single authorization code via concurrent token exchange requests that race the non-atomic find-then-delete operation against a shared relational database under READ_COMMITTED isolation. Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fixes this issue.

By default, StaxUtils placed no limit on the total number of elements or the total number of characters in an XML document. A very large request could therefore use a lot of memory and CPU during parsing, especially where CXF builds a DOM from the input (for example SAAJ or WS-Security), and could cause a denial of service when no request size limit was configured. Both limits now have defaults: the maximum element count is 100 × maxChildElements (5,000,000 by default), and the maximum document size is 256M characters. Applications that process larger documents can raise the limits with the org.apache.cxf.stax.maxElementCount and org.apache.cxf.stax.maxXMLCharacters properties. Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.

In Apache CXF, the parser for multipart/MTOM attachment part headers did not fully enforce the configured attachment-max-header-size (default 300 characters) and attachment-headers-max-count (default 500) limits. The size limit was applied only to each physical line, not to a header value built from continuation lines or to the combined values of a repeated header. The count limit was checked against the number of distinct header names, not the total number of header lines. A remote, unauthenticated attacker could send a multipart request with very large folded or repeated part headers. The server would then allocate memory without bound, causing a denial of service.  Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.

Improper Verification of Cryptographic Signature vulnerability in Apache CXF's JAX-RS XML Security module. The JAX-RS XML Signature interceptors (XmlSigInHandler, XmlSigInInterceptor and the streaming XmlSecInInterceptor) did not ensure that the XML passed to the application was covered by the signature. An attacker with any document signed by a trusted key could wrap it in unsigned content, which the application would then treat as signed. Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.

In Apache CXF's DefaultEncryptingOAuthDataProvider, revoked access tokens still decrypt successfully, and TokenIntrospectionService reports active:true. The same applies to refresh tokens. This violates the RFC stipulations that 'The authorization server MUST invalidate the token.' and 'introspection of a revoked token MUST return {"active":false}'. Users are recommended to upgrade to versions 4.2.3 or 4.1.8 or 3.6.12, which fix this issue.

A race condition in JCacheCodeDataProvider allows an attacker to redeem a single authorization code multiple times via concurrent requests, resulting in the issuance of multiple distinct, valid access tokens. Users are recommended to upgrade to versions 4.2.3, 4.1.8 or 3.6.12, which fix this issue.

Apache CXF reads a top-level WSDL through its hardened StaxUtils path, which disables XML DTDs and external entities. However, any <wsdl:import> or <xsd:import> referenced from that top-level WSDL is handed off to WSDL4J, which does not disable DOCTYPE declarations or external entities. As a result, the protections applied to the top-level document do not extend to imported documents, leaving imported WSDL/XSD content vulnerable to XML External Entity (XXE) attacks. Users are recommended to upgrade to versions 4.2.3 or 4.1.8 or 3.6.12, which fix this issue.

An incomplete fix for CVE-2026-50645 means that it is still possible to perform a denial of service attack on Apache CXF by sending a message with many attachment headers. Users are recommended to upgrade to versions 4.2.3 or 4.1.8 or 3.6.12, which fix this issue.

Apache CXF allows to set a limit on the number of form parameters in a JAX-RS message via the "maxFormParameterCount" configuration option. However, no default limit is set which may lead to denial of service attacks when processing  requests with very large numbers of form parameters. Users are recommended to upgrade to versions 4.2.3 or 4.1.8 or 3.6.12, which fix this issue by using a default limit of 500 parameters.

The OpenID Connect Core 1.0 specification mandates that the RP MUST validate the `c_hash` parameter when operating in the Hybrid Flow. If an Apache CXF RP is integrated with a non-compliant or misconfigured Identity Provider (IdP) that omits the `c_hash`, the RP becomes vulnerable to Authorization Code Substitution/Injection attacks. Users are recommended to upgrade to versions 4.2.3 or 4.1.8 or 3.6.12, which fix this issue.

Apache CXF allows to control the maximum attachment size via the "attachment-max-size". Prior to Apache CXF 4.2.3 and 4.1.8 and 3.6.12, there was no default placed on this size, meaning that a denial of service attack is possible if the user doesn't explicitly set the limit. Users should update to Apache CXF 4.2.3 or 4.1.8 or 3.6.12 which fixes this problem by imposing a default attachment size limit of 50mb.

There is no restriction on the amount of attachment headers that a message can contain when being deserialized by Apache CXF, which can lead to uncontrolled resource consumption or a denial of service attack. Users are recommended to upgrade to versions 4.2.2 or 4.1.7 or 3.6.12, which fix this issue by imposing a maximum default of 500 attachments per message.