CVE-2026-527239.1CriticalCWE-295

CVE-2026-52723: ePA 3.x Integration: VAU Server Authentication Bypass via Circular Certificate Trust

fbeta-GmbH · ePA3-Service-OpenSource

Affected: fbeta-GmbH ePA3-Service-OpenSource · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.4%probability of exploitation in the next 30 days

32nd percentile

050100

Higher than 32% of scored CVEs

9.1CriticalCVSS 3.1

LowMediumHighCrit.

DescriptionCVE.org

ePA 3.x Integration implements the authorization workflow and writes Medical Information Objects to Germany's electronic patient record. Prior to 1.3.0, ePA 3.x Integration performs VAU server certificate validation in app/vau/VAUProtokoll.py without anchoring the signed_vau_server_pub_keys and AUT_VAU_CertData certificate path to independent trusted material. A network-positioned attacker between the DiGA backend and the ePA system can intercept the VAU handshake, supply attacker-controlled certificate and key material, and satisfy the circular trust relationship. Because TLS certificate verification is also disabled in affected versions, no independent server-authentication layer prevents the attack. The attacker can impersonate the VAU server, control the negotiated session keys, and read or modify all encrypted VAU traffic. This issue is fixed in version 1.3.0.

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

fbeta-GmbH · ePA3-Service-OpenSource< 1.3.0

On the Atlas

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Exploitation: Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Improper Certificate Validation · Cryptography
Published: August 2026
Band: Unlikely (under 1%), August 2026

CoverageNo articles yet

No CyberSIXT article names CVE-2026-52723 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.