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CVE-2026-44900

epa4all-client: VAU Signature bypass

Published: May 26, 2026Updated: May 26, 2026 Sources: CVE List NVD
NVD MITRE
8.1CVSS
HIGH

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.

EPSS Score
N/A
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available

CVSS Vector Breakdown

AV:AAC:LPR:NUI:NS:UC:HI:HA:N
Exploitability
AV:AAttack Vector
Adjacent
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:NAvailability
None

Weaknesses

CWE-295

Affected Products

epa4all-client
oviva-ag
epa4all-client
com.oviva.telematik

Attack Graph

Products CVE Techniques Tactics

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Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

MITRE ATT&CK

1 technique
Collection
View detailed technique mapping

References

https://github.com/oviva-ag/epa4all-client/security/advisories/GHSA-g8r3-5hwf-qp96
github.com
https://github.com/oviva-ag/epa4all-client/pull/34
github.com

Timeline

Published
May 26, 2026
Last Updated
May 26, 2026

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