Insecure XML parser configuration in Apache CXF's WS-Transfer module may allow attackers to perform XXE attacks. Users are recommended to upgrade to versions 4.2.1, 4.1.6 or 3.6.11, which fix this issue.

The fix for CVE-2025-48913: Apache CXF: Untrusted JMS configuration can lead to RCE was not complete, meaning that another path in the code might lead to code execution capabilities, if untrusted users are allowed to configure JMS for Apache CXF. Users are recommended to upgrade to versions 4.2.1, 4.1.6 or 3.6.11, which fix this issue.

An LDAP injection vulnerability in the LDAP Certificate repository of the XKMS server in Apache CXF may allow an attacker to retrieve arbitrary certificates from the repository. Users are recommended to upgrade to versions 4.2.1, 4.1.6 or 3.6.11, which fix this issue.

A race condition in AbstractOAuthDataProvider allows concurrent requests using the same Refresh Token to bypass single-use semantics and generate multiple valid Access Tokens, when 'recycleRefreshTokens' is set to false. A leaked refresh token can be replayed concurrently by multiple attackers or threads. Users are recommended to upgrade to versions 4.2.2 or 4.1.7 or 3.6.12, which fixes this issue.

A JNDI Injection vulnerability has been discovered in Apache CXF's JCA integration module, which can allow for code execution, if an attacker is able to manipulate the JCA deployment descriptor (ra.xml) or runtime activation parameters. Users are recommended to upgrade to versions 4.2.2 or 4.1.7 or 3.6.12, which fixes this issue.

An authentication bypass vulnerability exists in the OAuth2 TokenIntrospectionService in Apache CXF. Due to a missing 'throw' keyword in the security context check, the introspection endpoint (/services/oauth2/introspect) can be accessed by any unauthenticated network attacker. However note that this is a safeguard only in the case that someone forgot to enable authentication on the service. Users are recommended to upgrade to version 4.2.2 or 4.1.7 or 3.6.12, which fixes this issue.

A CRLF injection vulnerability exists in the OAuth2 AuthorizationUtils class. When constructing the WWW-Authenticate response header, the 'realm' parameter is concatenated without sanitizing Carriage Return (CR) and Line Feed (LF) characters. If an attacker can control the realm value, they can inject arbitrary HTTP headers or split the HTTP response entirely. Users are recommended to upgrade to versions 4.2.2 or 4.1.7 or 3.6.12, which fixes this issue.

The JwtAccessTokenValidator class in Apache CXF fails to validate the 'aud' (Audience) claims of incoming JWT access tokens. This allows a JWT issued for one Resource Server to be successfully replayed against a completely different Resource Server, leading to Token Confusion/Routing attacks. Users are recommended to upgrade to versions 4.2.2 or 4.1.7 or 3.6.12, which fixes this issue.

A further incomplete fix for a previous advisory CVE-2026-44417 (Untrusted JMS configuration can lead to RCE) for Apache CXF has been identified, which can allow code execution capabilities, if untrusted users are allowed to configure JMS for Apache CXF. Users are recommended to upgrade to versions 4.2.2 or 4.1.7 or 3.6.12, which fixes this issue.

A logic error in OAuthRequestFilter rejects legitimate requests originating from the bound IP address, while blindly allowing requests from any other IP address. Enabling this

security feature inadvertently creates an inverse security check. Users are recommended to upgrade to versions 4.2.2 or 4.1.7 or 3.6.12, which fixes this issue.

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.

A vulnerability in Apache CXF's JwsJsonContainerRequestFilter can be exploited to cause CXF to process metadata that was not authenticated by the accepted signature. This can bypass the application's assumption

that accepted Content-Type or protected HTTP-header metadata came from a verified signature entry, and may steer downstream JAX-RS entity parsing or signed-header consistency checks. Users are recommended to upgrade to versions 4.2.2 or 4.1.7 or 3.6.12, which fix this issue.

The 'clientId' parameter from incoming HTTP requests is directly concatenated into OAuth2 server log warning messages without sanitizing control characters. This allows an attacker to inject arbitrary content, including fake log entries, into the server's log files. Users are recommended to upgrade to versions 4.2.2 or 4.1.7 or 3.6.12, which fixes this issue.

Apache CXF's JMS transport deserializes the body of any inbound JMS ObjectMessage using native Java deserialization, with no type restrictions in place. Any attacker able to place a message on the service's JMS destination can submit a malicious serialized object, leading to denial of service or, if a suitable gadget class is on the classpath, remote code execution. The fix disables ObjectMessage deserialization by default, with a configuration switch to re-enable it if needed. Users are recommended to upgrade to versions 4.2.3 or 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.

Apache CXF’s OIDC relying-party token validation could accept self-issued ID tokens without enforcing required claim checks (issuer/subject/audience/time and subjwk binding), enabling authentication bypass with crafted tokens. However, note that self-issued ID tokens are not accepted by default in the validator. Users are recommended to upgrade to versions 4.2.3 or 4.1.8 or 3.6.12, which fixes 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.

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.

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.

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 STSTokenValidator and Security Token Service (STS) cached validated security tokens under a non-cryptographic 32-bit hash of the token (Java Arrays.hashCode/hashCode()), and treated a cache hit as proof that the presented token had already been validated. An attacker could craft a token (for example a UsernameToken or a self-signed SAML Assertion) whose hash collides with a cached entry. The token would then be accepted without password validation, signature trust verification or a call to the STS. This could let the attacker authenticate as another user and, through STS token validation or renewal, obtain STS-signed tokens for that identity. 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.

Apache CXF's EndpointReferenceUtils and W3CMultiSchemaFactory classes construct a SAXParserFactory without the necessary JAXP hardening configurations, enabling out-of-band (OOB) external entity resolution. Users are recommended to upgrade to versions 4.2.2 or 4.1.7 or 3.6.12, which fix this issue.

The OpenID Connect Core 1.0 specification mandates that the RP MUST validate the chash 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 chash, 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's JwtRequestCodeFilter copies all claims from a signed request JWT into the authorization parameter map without excluding security-sensitive parameters. A client that can produce a validly-signed request JWT (e.g., one whose clientsecret is known or compromised) can thereby substitute the codechallenge, codechallengemethod, nonce, and state values that were set in the outer HTTP request, undermining PKCE integrity and OpenID Connect replay protection. Users are recommended to upgrade to versions 4.2.3 or 4.1.8 or 3.6.12, 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.

In Apache CXF's DefaultEncryptingCodeDataProvider, a captured authorization code can be redeemed an unlimited number of times due to a flaw in the implementation of the removeCodeGrant functionality. This violates the RFC requirement that "The authorization code MUST NOT be used more than once." Users are recommended to upgrade to versions 4.2.3 or 4.1.8 or 3.6.12, 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 READCOMMITTED isolation. Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fixes this issue.