Vulnerability Description
In liboauth2 the Demonstrating Proof-of-Possession (DPoP) verifier accepts a proof whose JSON Web Key (jwk) header contains private key material. RFC 9449 section 4.3 step 7 requires the verifier to reject such a proof but oauth2_token_verify() function returns success for a malformed DPoP proof that embeds the private Elliptic Curve (EC) key in the header. This issue was fixed in version 2.3.0
Related Weaknesses (CWE)
References
- https://cert.pl/en/posts/2026/07/CVE-2026-54430
- https://github.com/OpenIDC/liboauth2
- https://github.com/OpenIDC/liboauth2/commit/c0b57152ed6a0af33aeb04a60bd7f5bff5ab
FAQ
What is CVE-2026-54431?
CVE-2026-54431 is a documented vulnerability. In liboauth2 the Demonstrating Proof-of-Possession (DPoP) verifier accepts a proof whose JSON Web Key (jwk) header contains private key material. RFC 9449 section 4.3 step 7 requires the verifier to r...
How severe is CVE-2026-54431?
CVSS scoring is not yet available for CVE-2026-54431. Check NVD for updates.
Is there a patch for CVE-2026-54431?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.