CVE-2026-21857

Severity CVSS v4.0:

HIGH

Type:

CWE-22 Path Traversal

Publication date:

07/01/2026

Last modified:

20/01/2026

Description

REDAXO is a PHP-based content management system. Prior to version 5.20.2, authenticated users with backup permissions can read arbitrary files within the webroot via path traversal in the Backup addon&#39;s file export functionality. The Backup addon does not validate the `EXPDIR` POST parameter against the UI-generated allowlist of permitted directories. An attacker can supply relative paths containing `../` sequences (or even absolute paths inside the document root) to include any readable file in the generated `.tar.gz` archive. Version 5.20.2 fixes this issue.

Impact

Vector 4.0

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

Base Score: 8.30 HIGH
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:N

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

Base Score 4.0

8.30

Severity 4.0

HIGH

Vector 3.x

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

Base Score: 6.50 MEDIUM
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N

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