CVEvulnerability

CVE-2026-85751

9.8 CRITICAL Published 2026-09-21 Modified 2026-09-24 Official page ↗
Status
Deferred
Published
2026-09-21
Last modified
2026-09-24
Assigner
[email protected]
CVSS 3.1 ([email protected])
9.8 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weaknesses
CWE-290, CWE-807

Description

Mailu is a mail server distributed as a set of Docker images. From Mailu 2.0 until 2024.06.55 and prior to Mailu helm-charts 2.7.3, deployments with PROXY_AUTH_WHITELIST configured but REAL_IP_HEADER unset trusted a client-controlled X-Forwarded-By header for header-based proxy authentication. The proxy_hide_header directive in the nginx template at core/nginx/conf/proxy.conf hid the header from upstream responses but did not overwrite the incoming request value in this configuration. An unauthenticated remote attacker could therefore spoof the trusted proxy identity and bypass authentication. This issue is fixed in Mailu 2024.06.55 and Mailu helm-charts 2.7.3.

Related

Weakness · CWE (2)

  • CWE-290 Authentication Bypass by Spoofing weakness
  • CWE-807 Reliance on Untrusted Inputs in a Security Decision weakness

References