SB2025060309 - Improper input validation in Craft CMS
Published: June 3, 2025
Security Bulletin ID
SB2025060309
Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Input validation error (CVE-ID: CVE-2025-35939)
The vulnerability allows a remote attacker to write arbitrary contents to session files.
The vulnerability exists due to Craft CMS does not sanitize data before writing them into session files with predictable file names and location. A remote attacker can abuse this to write arbitrary PHP code into a known location of the system and later execute it using a different vulnerability.
Remediation
Install update from vendor's website.