CVE-2026-44900

epa4all-client: VAU Signature bypass

Published May 26, 2026 CVSS 3.1 · 8.1 High EPSS < 1% KEV · Not listed
Description
epa4all-client is the Java Client for epa4all / ePA 3.0 in the Telematik Infrastruktur. Prior to 1.2.1, in SignedPublicKeysTrustValidatorImpl.isTrusted(), the ECDSA signature verification at line 45 discards the boolean return value of Signature.verify(). The method performs certificate chain validation, OCSP check, and signature algorithm setup, but never checks whether the signature actually matches. For any structurally valid signature, it returns true. This vulnerability is fixed in 1.2.1.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

Source ID Title
Github GHSA Github GHSA GHSA-g8r3-5hwf-qp96 epa4all-client has a VAU Signature bypass
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Com.oviva.telematik
Com.oviva.telematik epa4all-client
Oviva-ag
Oviva-ag epa4all-client
Vendors & Products Com.oviva.telematik
Com.oviva.telematik epa4all-client
Oviva-ag
Oviva-ag epa4all-client
Type Values Removed Values Added
Description epa4all-client is the Java Client for epa4all / ePA 3.0 in the Telematik Infrastruktur. Prior to 1.2.1, in SignedPublicKeysTrustValidatorImpl.isTrusted(), the ECDSA signature verification at line 45 discards the boolean return value of Signature.verify(). The method performs certificate chain validation, OCSP check, and signature algorithm setup, but never checks whether the signature actually matches. For any structurally valid signature, it returns true. This vulnerability is fixed in 1.2.1.
Title epa4all-client: VAU Signature bypass
Weaknesses CWE-295
References
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
May 28, 2026, 2:12 PM
Reserved
May 7, 2026, 9:50 PM
Status
Deferred
Published
May 26, 2026, 10:16 PM
Modified
Jul 24, 2026, 11:10 AM