Actively exploited · Published May 7, 2025 · Assigned by cisa-cg
CVE-2025-35939Craft CMS stores user-provided content in session files
Medium 5.3 Exploited
In plain English
A medium-severity security flaw in CMS from Craft. Attackers are actively exploiting it in the wild (listed by CISA on June 2, 2025). The chance it is exploited in the next 30 days is estimated at 1.3% (higher than 72% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
CISA guidance
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Federal agencies must remediate by Jun 23, 2025.
Official description
Craft CMS stores arbitrary content provided by unauthenticated users in session files. This content could be accessed and executed, possibly using an independent vulnerability. Craft CMS redirects requests that require authentication to the login page and generates a session file on the server at '/var/lib/php/sessions'. Such session files are named 'sess_[session_value]', where '[session_value]' is provided to the client in a 'Set-Cookie' response header. Craft CMS stores the return URL requested by the client without sanitizing parameters. Consequently, an unauthenticated client can introduce arbitrary values, such as PHP code, to a known local file location on the server. Craft CMS versions 5.7.5 and 4.15.3 have been released to address this issue.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Packagist | craftcms/cms | 5.7.5 | GHSA-7vrx-9684-xrf2 |
| Packagist | craftcms/cms | 4.15.3 | GHSA-7vrx-9684-xrf2 |
Affected products (as reported)
Weakness: CWE-472 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N