CVE-2026-54431

MEDIUMPre-NVD 5.15.1—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.1%, top 97% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 4 sources updated this week
5.1
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.1Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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

CVSS v3
5.1
EG Score
5.1(medium)
EPSS
2.8%
KEV
Not listed

Published

July 2, 2026

Last Modified

July 2, 2026

Advisory Details (3)

Auto-updated Jul 3, 2026
Patch available. Sources: github_commit.
github_commit

commit c0b57152ed6a (OpenIDC/liboauth2)

Fix landed in OpenIDC/liboauth2 commit c0b57152ed6a — awaiting tagged release

https://github.com/OpenIDC/liboauth2/commit/c0b57152ed6a0af33aeb04a60bd7f5bff5ab8800
generic

GitHub - OpenIDC/liboauth2: OAuth 2.x and OpenID Connect C library · GitHub

https://github.com/OpenIDC/liboauth2
generic Patch Available

Vulnerabilities in OpenIDC liboauth2 software | CERT Polska

https://cert.pl/en/posts/2026/07/CVE-2026-54430

Vendor Advisories for CVE-2026-54431(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 21× in last 7d / 21× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-06 16:27 UTCEPSS rescore
  2. 2026-07-06 16:27 UTCEPSS rescore
  3. 2026-07-06 15:22 UTCEG score recompute
  4. 2026-07-06 15:21 UTCGHSA enrichment
  5. 2026-07-06 02:23 UTCEPSS rescore
  6. 2026-07-06 02:23 UTCEPSS rescore
  7. 2026-07-05 15:45 UTCEG score recompute
  8. 2026-07-05 15:45 UTCGHSA enrichment
  9. 2026-07-05 02:31 UTCEPSS rescore
  10. 2026-07-05 02:30 UTCEPSS rescore
  11. 2026-07-04 16:10 UTCEG score recompute
  12. 2026-07-04 16:09 UTCGHSA enrichment
  13. 2026-07-04 06:31 UTCEPSS rescore
  14. 2026-07-04 06:31 UTCEPSS rescore
  15. 2026-07-03 16:34 UTCEG score recompute
  16. 2026-07-03 16:33 UTCGHSA enrichment
  17. 2026-07-02 16:59 UTCEG score recompute▲ 5.10
  18. 2026-07-02 16:59 UTCGHSA enrichment
  19. 2026-07-02 16:58 UTCNVD updateCVSS v3 → 5.1 · CVSS v4 → 5.1
  20. 2026-07-02 12:36 UTCEG score recompute
  21. 2026-07-02 12:36 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-54431?
CVE-2026-54431 is a medium vulnerability published on July 2, 2026. 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 oauth2tokenverify() function returns success for a malformed DPoP proof that…
When was CVE-2026-54431 disclosed?
CVE-2026-54431 was first published in the National Vulnerability Database on July 2, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-54431 actively exploited?
CVE-2026-54431 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-54431?
CVE-2026-54431 has a CVSS v3 base score of 5.1 (NVD).
How do I remediate CVE-2026-54431?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-54431, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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