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Vulnerability record · public intelligence
CVE-2026-54431
MEDIUM

Improper Data Validation in liboauth2

Published Jul 2, 2026 · Updated Nov 3, 2026

Severity · CVSSMEDIUM · Not scored
Known exploitationNot listed
EPSS / likelihood0.18%
QFinch risk scoreNot available

Original summary

Normalized public record · Updated Nov 3, 2026

Improper Data Validation in liboauth2

Publisher and source text is retained separately from QFinch interpretation.

QFinch assessment

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.

Evidence: public source records

Affected products

Affected scope reported by the available public evidence
Affected package, product or rangeFix status
Consult the referenced vendor advisory for affected versions.Consult source advisory

Matching a version is only one part of assessing exposure. QFinch has not assessed your environment on this public page.

Remediation

Apply the vendor-supported fixed release or mitigation, then verify the affected component is no longer reachable.

  1. Confirm the affected product and reachable code path exist in your environment.
  2. Apply the vendor-supported patch or mitigation from the primary advisory.
  3. Rescan the exact deployed revision and retain verification evidence.
Review primary references

Evidence coverage

FIRST-EPSSCVE-LIST-V5NVD-MODIFIED
SSVC priority
LOW
Confidence
Not available
Aliases
None reported

Scores appear only when corresponding evidence exists. Missing data is never interpreted as zero risk.

Sources and record history

  1. cert.pl ↗
  2. Source repository ↗
  3. Patch commit ↗

Record history

Published Jul 2, 2026 · Last refreshed Nov 3, 2026