Improper Input Validation Affecting adminer package, versions <6.0.0-1


Severity

Recommended
0.0
medium
0
10

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Threat Intelligence

EPSS
0.21% (11th percentile)

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  • Snyk IDSNYK-DEBIANUNSTABLE-ADMINER-19270571
  • published27 Aug 2026
  • disclosed25 Aug 2026

Introduced: 25 Aug 2026

NewCVE-2026-34959  (opens in a new tab)
CWE-20  (opens in a new tab)

How to fix?

Upgrade Debian:unstable adminer to version 6.0.0-1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream adminer package and not the adminer package as distributed by Debian. See How to fix? for Debian:unstable relevant fixed versions and status.

Adminer 4.6.0 before 5.5.0 prepends the client-supplied X-Forwarded-Prefix header to $_SERVER["REQUEST_URI"] with no trusted-proxy check and no validation of the prefix value. An attacker can supply an absolute URL (e.g. X-Forwarded-Prefix: https://evil.example) that flows into Location redirect headers, the Set-Cookie path attribute, and self-referential links. This enables an authenticated open redirect after state-changing POSTs, unauthenticated control of the session cookie path attribute, and poisoning of self-referential links; CR/LF cannot be injected, so header splitting/XSS is not possible.

CVSS Base Scores

version 3.1