CVE-2026-34959

Severity CVSS v4.0:

MEDIUM

Type:

CWE-20 Input Validation

Publication date:

25/08/2026

Last modified:

25/08/2026

Description

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.

Impact

Vector 4.0

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N CVSS v4.0 Severity and Metrics:

Base Score: 5.30 MEDIUM
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Attack Requirements (AT): None
Privileges Required (PR): None
User Interaction (UI): Passsive
Confidentiality (VC): None
Integrity (VI): Low
Availability (VA): None
Confidentiality (SC): None
Integrity (SI): Low
Availability (SA): None

Base Score 4.0

5.30

Severity 4.0

MEDIUM

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N CVSS v3.1 Severity and Metrics:

Base Score: 4.70 MEDIUM
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): Required
Scope (S): Changed
Confidentiality (C): None
Integrity (I): Low
Availability (A): None

Base Score 3.x

4.70

Severity 3.x

MEDIUM

CVE-2026-34959

Description

Impact

References to Advisories, Solutions, and Tools