CVE-2026-34959

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 v3 4.7 MEDIUM

4.7^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/vrana/adminer/security/advisories/GHSA-8478-xrj3-h9c2
https://www.vulncheck.com/advisories/adminer-before-open-redirect-via-x-forwarded-prefix
https://github.com/vrana/adminer/security/advisories/GHSA-8478-xrj3-h9c2

Configurations

No configuration.

History

12 Oct 2026, 15:10

Type	Values Removed	Values Added
Summary		(es) Adminer 4.6.0 anterior a 5.5.0 antepone el encabezado X-Forwarded-Prefix proporcionado por el cliente a $_SERVER[“REQUEST_URI”] sin verificación de proxy de confianza y sin validación del valor del prefijo. Un atacante puede proporcionar una URL absoluta (p. ej., X-Forwarded-Prefix: https://evil.example) que se incorpora a los encabezados de redirección Location, al atributo de ruta de Set-Cookie y a los enlaces autorreferenciales. Esto permite una redirección abierta autenticada después de POSTs que cambian el estado, control no autenticado del atributo de ruta de la cookie de sesión y el envenenamiento de enlaces autorreferenciales; no se puede inyectar CR/LF, por lo que la división de encabezados/XSS no es posible.

Information

Published : 2026-08-25 02:16

Updated : 2026-10-12 15:10

NVD link : CVE-2026-34959

Mitre link : CVE-2026-34959

CVE.ORG link : CVE-2026-34959

JSON object : View

Products Affected

No product.

CWE

CWE-20

Improper Input Validation

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