CVE-2026-54431 | BDVDB-2026-345225 Detail

OpenIDCliboauth2

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

Impact#

Per CVSS v4.0: confidentiality impact low, integrity impact none, availability impact none. Attack vector: local.

Weaknesses#

CWE-358 Improperly Implemented Security Check for Standard

References#

Exploit#

No public exploit known

History#

Version 12026-07-02Record published in the CVE List.

Published

Published: 2026-07-02
Last modified: 2026-07-02

Vendor information

Vendor: OpenIDC
Product: liboauth2

All OpenIDC vulnerabilities

Score

5.1 Medium

EPSS

less than 1%, Very Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 7.4.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Not classified

Action

No specific action is recorded in the source data. Check the references for vendor guidance.

Affected Systems

Vulnerable
< 2.3.0
Fixed
2.3.0

Scoring System

CVSS v4.0

5.1 Medium

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

Metric breakdown
Attack Vector	Local
Attack Complexity	Low
Attack Requirements	None
Privileges Required	None
User Interaction	None
Vulnerable System Confidentiality	Low
Vulnerable System Integrity	None
Vulnerable System Availability	None
Subsequent System Confidentiality	None
Subsequent System Integrity	None
Subsequent System Availability	None

CVSS v3.1

Not available

CVSS v3.0

Not available

CVSS v2

Not available

Source: CVE List v5 (record); CISA KEV (kev, action); FIRST EPSS (epss).