Known exploited vulnerability
CVE-2025-35939
The short answer
CVE-2025-35939 affects Craft CMS and is rated medium (CVSS 6.9). CISA added it to the Known Exploited Vulnerabilities catalog on 2025-06-02: attackers are using it, so patch it first. Fixed versions are published for craftcms/cms (5.7.5, 4.15.3).
What it is
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.
Weakness: CWE-472.
Severity
6.9 medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Exploited (CISA KEV)
Yes, since Jun 2, 2025
Federal due date Jun 23, 2025
EPSS, next 30 days
1.4%
Higher than 72% of scored CVEs
How it can be exploited
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- None
- User interaction
- None
- Confidentiality impact
- None
- Integrity impact
- Low
- Availability impact
- None
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.
Affected packages and fixed versions
| Package | Ecosystem | Fixed in | Advisory |
|---|---|---|---|
| craftcms/cms | Packagist | 5.7.5, 4.15.3 | GHSA-7vrx-9684-xrf2 |
Is it in your code? Drop your lockfile into the free vulnerability check, or let vulnerability watch check your repository every day and open the upgrade as a pull request.
Affected products
CMS. NVD's record lists the exact affected versions.
References
- github.com/craftcms/cms/pull/17220 Patch
- github.com/craftcms/cms/releases/tag/4.15.3 Release Notes
- github.com/craftcms/cms/releases/tag/5.7.5 Release Notes
- raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2025/va-25-147-01.json Third Party Advisory
- www.cve.org/CVERecord?id=CVE-2025-35939 VDB Entry
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-35939 US Government Resource
Questions
Is CVE-2025-35939 being exploited?
Yes. CISA added CVE-2025-35939 to its Known Exploited Vulnerabilities catalog on 2025-06-02, with a federal remediation due date of 2025-06-23.
How do I fix CVE-2025-35939?
Upgrade to a fixed version: craftcms/cms (Packagist) 5.7.5 or 4.15.3. 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.
From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.
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