CVE-2025-35939

Craft CMS stores arbitrary content provided by unauthenticated users in session files. This content could be accessed and executed, possibly using…

Browse: All 2025 CVEs · All vendors

CVSS score
5.3 Medium
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
CISA KEV
Yes — actively exploited (added 2025-06-02, remediation due 2025-06-23)
Weakness (CWE)
CWE-472, NVD-CWE-Other
Published
2025-05-07
Last modified
2026-06-17
NVD status
Analyzed

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 products

Affected ranges per NVD CPE data; confirm exact versions in the vendor advisory.

Required action (CISA)

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 remediation deadline: 2025-06-23.

How to prioritize this

This vulnerability is on the CISA KEV list, meaning it is being actively exploited — treat it as urgent regardless of the raw CVSS number. Use the live CVE lookup for the latest NVD data, and the CVSS 3.1 calculator to model your own environmental score.

References

FAQ

Is CVE-2025-35939 actively exploited?

Yes. CISA added CVE-2025-35939 to its Known Exploited Vulnerabilities (KEV) catalog on 2025-06-02, with a federal remediation deadline of 2025-06-23. A KEV listing means real-world exploitation is confirmed, so patching this should be prioritized above many higher-CVSS bugs that aren't being exploited.

What is the CVSS score of CVE-2025-35939?

CVE-2025-35939 has a CVSS base score of 5.3 (Medium). Its vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

Related vulnerabilities

Data source: NVD & CISA KEV. Shown as-is; nothing added. Last generated from NVD data — re-check the live tool for updates.