CVE-2025-35939
Craft CMS: External Control of Assumed-Immutable Web Parameter
As of , CVE-2025-35939 in Craft CMS is on CISA's list of exploited vulnerabilities: CISA listed it on . Our patch-first group: Patch soon.
- Exploited
- Yes: CISA listed it on 2 June 2025
- US federal deadline
- 23 June 202521 days after CISA listed it. US federal civilian agencies must fix it by then.
- Used in ransomware campaigns
- Not known to CISA
- EPSS score
- 0.01Higher than 70% of the CVEs EPSS scores. EPSS estimates the chance of exploitation activity in the next 30 days.
- Public exploit
- None foundNeither Metasploit nor Exploit-DB lists one.
- Fix
- Vendor advice: github.comLinks below, from CISA's entry.
What CISA says to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CISA's required action
What the flaw is
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's 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.
The CVE record's description, from cisa-cg
- CVE published
- 7 May 2025
- Assigned by
- cisa-cg
- CVSS
- 6.9 Medium (CVSS 4.0, from the CNA)
- CWE-472
- External Control of Assumed-Immutable Web Parameter
- CISA SSVC, exploitation
- active
- CISA SSVC, automatable
- yes
- CISA SSVC, technical impact
- partial
Timeline
- The CVE record was published.
- CISA added it to its list of exploited vulnerabilities.
- The US federal deadline to fix it.
Craft CMS: other exploited entries
| Vulnerability | Product | Our group | Listed | Deadline | EPSS |
|---|---|---|---|---|---|
| CVE-2025-32432Code Injection | Craft CMS Craft CMS | Patch this weekMetasploit module; EPSS 0.99 | 0.99 | ||
| CVE-2024-56145Code Injection | Craft CMS Craft CMS | Patch this weekMetasploit module; EPSS 0.97 | 0.97 | ||
| CVE-2025-23209Code Injection | Craft CMS Craft CMS | Patch soon | 0.22 |
Read further
- CVE recordcve.org
- NVD entrynvd.nist.gov
- CISA's catalogcisa.gov
- EPSS for this CVEapi.first.org