# CVE-2026-100227: Apache CXF XML signature verification bypass in JAX-RS

Source: https://junglewise.ai/threats/cve-2026-100227-improper-verification-of-cryptographic-signature-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-09. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-100227 · Severity: high · CVSS 7.5 · Published 2026-10-09

Apache CXF is a web services framework used by many Java applications. This vulnerability allows an attacker to tamper with XML documents by wrapping a legitimately signed document in unsigned content, which the application will incorrectly treat as signed. This could lead to unauthorized data modification or access if the application relies on XML signatures for security decisions.

Technologies: [Apache CXF](https://junglewise.ai/threats/technologies/apache-cxf). Vendors: [Apache](https://junglewise.ai/threats/vendors/apache).

## Quick answers

**Is CVE-2026-100227 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-100227 being exploited in the wild.

**How severe is CVE-2026-100227?** High severity, with a CVSS score of 7.5, published 9 October 2026.

**Which products and versions are affected?** Apache CXF before 3.6.13, 4.1.9, 4.2.4.

**Is there a fix for CVE-2026-100227?** Yes: fixed in CXF 3.6.13, 4.1.9, 4.2.4. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-100227 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-100227?** Check whether you run Apache CXF at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in CXF 3.6.13, 4.1.9, 4.2.4

## Technical details

The JAX-RS XML Signature interceptors (XmlSigInHandler, XmlSigInInterceptor, and XmlSecInInterceptor) fail to verify that all XML content processed by the application is covered by the signature. An attacker can take a document signed with a trusted key, wrap it in unsigned XML content, and the vulnerable interceptors will process the unsigned portions without detecting the tampering, treating the entire document as authenticated.

## Affected products

- Apache CXF before 3.6.13, 4.1.9, 4.2.4

## Timeline

- 2026-10-09: disclosed

## References

- [https://repo.maven.apache.org/maven2](https://repo.maven.apache.org/maven2)
- [https://lists.apache.org/thread.html/pst2oopnwt2rwhvkvmt5gdgwn36kq05m](https://lists.apache.org/thread.html/pst2oopnwt2rwhvkvmt5gdgwn36kq05m)

## Related threats

- [Apache CXF hash collision bypass in STS token validation](https://junglewise.ai/threats/cve-2026-97468-apache-cxf-s-ststokenvalidator-and-security-token-service-sts)
- [Apache CXF FIQL query parser ReDoS in operator search](https://junglewise.ai/threats/cve-2026-86463-apache-cxf-s-fiql-query-parser-has-a-vulnerability-in-how-it)
- [Apache CXF OIDC relying-party open redirect after authentication](https://junglewise.ai/threats/cve-2026-79650-apache-cxf-s-oidc-relying-party-component-could-redirect-users-to)
- [Apache CXF CompressionUtils.inflate() zip bomb](https://junglewise.ai/threats/cve-2026-78384-compressionutils-inflate-decompressed-attacker-controlled-deflate)
- [Apache CXF race condition in OAuth2 authorization code grant](https://junglewise.ai/threats/cve-2026-73179-improper-enforcement-of-single-use-authorization-code-semantics)