Is CVE-2026-54431 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-54431 being exploited in the wild.

How severe is CVE-2026-54431?

Informational severity, with a CVSS score of 5.1, published 2 July 2026.

Is there a fix for CVE-2026-54431?

A patch was published on 2026-06-02: Fix committed to repository Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-54431 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-54431?

Check whether you run Openidc Liboauth2 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.

CVE-2026-54431: OpenIDC liboauth2 improper security check in DPoP verifier

CVE-2026-54431 · Severity: info · CVSS 5.1 · Published 2026-07-02

OpenIDC liboauth2 is a library used to handle OAuth 2.0 and OpenID Connect authentication. A vulnerability in its DPoP (Demonstrating Proof-of-Possession) verification component allows malformed security proofs to be accepted even when they contain sensitive private key material. This could potentially lead to the exposure of cryptographic keys or the bypass of certain security checks intended to verify the sender's identity.

Vendors: Openidc.

Quick answers

Is CVE-2026-54431 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-54431 being exploited in the wild.
How severe is CVE-2026-54431?: Informational severity, with a CVSS score of 5.1, published 2 July 2026.
Which products and versions are affected?: Openidc Liboauth2 < 2.3.0.
Is there a fix for CVE-2026-54431?: A patch was published on 2026-06-02: Fix committed to repository Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-54431 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-54431?: Check whether you run Openidc Liboauth2 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.

Technical details

A vulnerability exists in liboauth2's DPoP verifier where the oauth2_token_verify() function fails to reject proofs containing private key material in the JWK header. This violates RFC 9449 section 4.3 step 7, which mandates that verifiers must reject such proofs. The root cause is located in the _oauth2_dpop_parse_and_validate() function within src/dpop.c, which returns success for malformed proofs embedding private Elliptic Curve (EC) keys. An attacker could potentially exploit this improper security check (CWE-358) to submit invalid proofs that should be discarded. The issue is resolved in version 2.3.0.

Affected products

OpenIDC liboauth2 < 2.3.0

Timeline

2026-06-02: patched: Fix committed to repository
2026-07-02: disclosed: CVE published by CERT.PL

References

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