Security Vulnerability in Apache CXF's JwtRequestCodeFilter
CVE-2026-63687

9.1CRITICAL

Key Information:

Vendor

Apache
Status
Apache Cxf
Vendor
CVE Published:
6 August 2026

What is CVE-2026-63687?

The JwtRequestCodeFilter in Apache CXF exposes a critical security vulnerability by copying all claims from a signed request JWT into the authorization parameter map, neglecting to exclude security-sensitive parameters. This flaw allows a malicious client that can produce a validly-signed request JWT to manipulate crucial values such as code_challenge, code_challenge_method, nonce, and state that are essential for PKCE integrity and OpenID Connect replay protection. Users are strongly advised to upgrade to the latest versions (4.2.3, 4.1.8, or 3.6.12) to mitigate this risk.

Affected Version(s)

Apache CXF 4.2.0 < 4.2.3

Apache CXF 4.0.0 < 4.1.8

Apache CXF 0 < 3.6.12

References

https://lists.apache.org/thread/drcq4chmt0btx86f17o47j17r...
vendor-advisory

CVSS V3.1

Score:
9.1
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Guanping Zhang reported this vulnerability.
.