CVE-2025-35939
MediumExploitedPublic exploitCraft CMS stores arbitrary content provided by unauthenticated users in session files
Published May 8, 2025 · Updated Aug 12, 2026 · Also known as GHSA-7vrx-9684-xrf2
Key Facts
Patch immediately- CVE-2025-35939 is a medium-severity vulnerability (CVSS 6.9 v4) affecting Craft CMS (Craftcms), craftcms/cms (composer).
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Jun 2, 2025. Public exploit code is available.
- EPSS estimates a 1.3% probability of exploitation in the next 30 days.
- Fixed versions are available, including Craft CMS 4.15.3, Craft CMS 5.7.5, craftcms/cms 4.15.3.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v4
6.9
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
EPSS (30-day exploit likelihood)
1.3%
Higher than 71.0% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2025-35939 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Jun 2, 2025 | Jun 23, 2025 | Not reported |
| Industry KEV feed | Jun 2, 2025 | Jun 23, 2025 | Not reported |
| CIRCL KEV | Jun 2, 2025 | Jun 23, 2025 | Not reported |
| ENISA EUVD | Jun 2, 2025 | n/a | Not reported |
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.
Affected Products
3 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Craft CMSCraftcms | See advisory | 4.15.3 |
| craftcms/cmscomposer | >= 5.0.0-alpha.1 | 4.15.3 |
Patched Releases
Craft CMS
4.15.3, 5.7.5
craftcms/cms
4.15.3, 5.7.5
Timeline
Publicly disclosed
May 8, 2025
Added to CISA KEV
Jun 2, 2025
Added to Industry KEV feed
Jun 2, 2025
Added to CIRCL KEV
Jun 2, 2025
Added to ENISA EUVD
Jun 2, 2025
Last updated
Aug 12, 2026
Weakness Type
- CWE-472 External Control of Assumed-Immutable Web Parameter
References
- advisoryGHSA advisory
- advisoryhttps://github.com/craftcms/cms/commit/e4c7bac8f31010aee048409f9ef6f744a83146b2
- advisoryhttps://github.com/CVEProject/cvelistV5/tree/main/cves/2025/35xxx/CVE-2025-35939.json
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2025-35939
- advisoryurl
FAQ
Common Questions.
Craft CMS stores arbitrary content provided by unauthenticated users in session files.
Affected: Craft CMS (Craftcms); craftcms/cms (composer) versions >= 5.0.0-alpha.1. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Jun 2, 2025.
Yes. It was added on Jun 2, 2025 with a federal remediation due date of Jun 23, 2025.
Public exploit code is available.
Fixed versions are available, including Craft CMS 4.15.3, Craft CMS 5.7.5, craftcms/cms 4.15.3.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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