CVE-2025-35939: in the CISA KEV catalogue
Craft CMS External Control of Assumed-Immutable Web Parameter Vulnerability. CISA added CVE-2025-35939 to the Known Exploited Vulnerabilities catalogue on 2025-06-02 with a default due date of 2025-06-23. Known ransomware campaign use: Unknown. Forensic triage flag: No.
Craft CMS contains an external control of assumed-immutable web parameter vulnerability. This vulnerability could allow an unauthenticated client to introduce arbitrary values, such as PHP code, to a known local file location on the server. This vulnerability could be chained with CVE-2024-58136 as represented by CVE-2025-32432. (CISA description)
- Vendor / product
- Craft CMS Craft CMS
- CWE
- CWE-472
- CISA required action
- Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- EPSS
- 1.3%, percentile 71 (scored 2026-11-03)
EPSS puts about 1.3 in 100 odds (1.3%) on exploitation activity being observed in the next 30 days. Its score is higher than or equal to that of 71% of scored CVEs. This is a model estimate about exploitation anywhere, not about your environment.
Vendor and reference links (from CISA)
Your own deadline under CISA BOD 26-04 depends on exposure, automatability and technical impact: work it out with the BOD 26-04 calculator.
Frequently asked questions
Is CVE-2025-35939 in the CISA KEV catalogue?
Yes. CISA added CVE-2025-35939 (Craft CMS External Control of Assumed-Immutable Web Parameter Vulnerability) to the Known Exploited Vulnerabilities catalogue on 2025-06-02. CISA's default due date for it is 2025-06-23.
Is CVE-2025-35939 used in ransomware attacks?
CISA marks known ransomware campaign use as Unknown for CVE-2025-35939. That means CISA lacks confirmation, not that ransomware groups do not use it.
What should I do about CVE-2025-35939?
CISA's required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Sources
- CISA, Known Exploited Vulnerabilities Catalog (accessed 2026-11-03)
- FIRST, Exploit Prediction Scoring System (EPSS) (EPSS by FIRST; scores generated by Empirical Security)
- NVD record for CVE-2025-35939