CVE-2026-44900

HIGH

epa4all-client: VAU Signature bypass

Title source: cna
STIX 2.1

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.

References (2)

Core 2
Core References
X_Refsource_Misc x_refsource_misc
https://github.com/oviva-ag/epa4all-client/pull/34

Scores

CVSS v3 8.1
EPSS 0.0012
EPSS Percentile 2.2%
Attack Vector ADJACENT_NETWORK
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-295
Status published
Products (3)
com.oviva.telematik/epa4all-client 0 - 1.2.1Maven
com.oviva.telematik/epa4all-client < 1.2.1
oviva-ag/epa4all-client < 1.2.1
Published May 26, 2026
Tracked Since May 27, 2026