OpenIDC liboauth2 up to 2.2.x oauth2_token_verify security check

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.3$0-$5k0.68

Summaryinfo

A vulnerability marked as problematic has been reported in OpenIDC liboauth2 up to 2.2.x. Affected by this issue is the function oauth2_token_verify. The manipulation leads to security check. This vulnerability is uniquely identified as CVE-2026-54431. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in OpenIDC liboauth2 up to 2.2.x and classified as problematic. This issue affects the function oauth2_token_verify. The manipulation with an unknown input leads to a security check vulnerability. Using CWE to declare the problem leads to CWE-358. The product does not implement or incorrectly implements one or more security-relevant checks as specified by the design of a standardized algorithm, protocol, or technique. The impact remains unknown. The summary by CVE is:

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

It is possible to read the advisory at cert.pl. The identification of this vulnerability is CVE-2026-54431 since 06/15/2026. The exploitation is known to be easy. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1211 according to MITRE ATT&CK.

Upgrading to version 2.3.0 eliminates this vulnerability. Applying the patch c0b57152ed6a0af33aeb04a60bd7f5bff5ab8800 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-41277). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.5
VulDB Meta Temp Score: 5.3

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Security check
CWE: CWE-358
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: liboauth2 2.3.0
Patch: c0b57152ed6a0af33aeb04a60bd7f5bff5ab8800

Timelineinfo

06/15/2026 CVE reserved
07/02/2026 +17 days Advisory disclosed
07/02/2026 +0 days VulDB entry created
07/02/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: cert.pl
Status: Confirmed

CVE: CVE-2026-54431 (🔒)
GCVE (CVE): GCVE-0-2026-54431
GCVE (VulDB): GCVE-100-375827
EUVD: 🔒

Entryinfo

Created: 07/02/2026 13:44
Updated: 07/02/2026 14:14
Changes: 07/02/2026 13:44 (56), 07/02/2026 14:14 (1)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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