CVE-2025-35939: Craft CMS External Control of Assumed-Immutable Web Parameter Vulnerability

CISA Known Exploited Vulnerabilities

Name

Craft CMS External Control of Assumed-Immutable Web Parameter Vulnerability

Vendor

Craft CMS

Product

Craft CMS

Added to the catalog

2025-06-02

Due date for US federal agencies

2025-06-23

Weaknesses

CWE-472

Catalog version

2026.10.30

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.

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.

Ransomware use: CISA does not mark known use of this vulnerability in ransomware campaigns.

Links in CISA's notes

• https://github.com/craftcms/cms/pull/17220
• https://nvd.nist.gov/vuln/detail/CVE-2025-35939

Read on 2026-11-02T23:39:54.475Z under licence cisa-kev-cc0@b0067899 from https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

NVD analysis

Status

Analyzed

Published

2025-05-07T23:15:54.103

Last modified

2026-06-17T09:14:18.460

Weaknesses

CWE-472, NVD-CWE-Other

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.

References

• https://github.com/craftcms/cms/pull/17220 (Patch)
• https://github.com/craftcms/cms/releases/tag/4.15.3 (Release Notes)
• https://github.com/craftcms/cms/releases/tag/5.7.5 (Release Notes)
• https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2025/va-25-147-01.json (Third Party Advisory)
• https://www.cve.org/CVERecord?id=CVE-2025-35939 (VDB Entry)
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-35939 (US Government Resource)

This product uses the NVD API but is not endorsed or certified by the NVD.

Read on 2026-11-02T23:42:22.836Z under licence nvd-api-terms-of-use@ff2a5288 from https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2025-35939

CVE record

Title (CNA)

Craft CMS stores user-provided content in session files

Assigner

cisa-cg

State

PUBLISHED

Published

2025-05-07T22:41:29.728Z

Updated

2026-02-26T18:28:42.701Z

Problem types

CWE-472 External Control of Assumed-Immutable Web Parameter

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.

References

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Read on 2026-11-03T02:16:20.211Z under licence cve-terms-of-use@81bfa2f3 from https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2025/35xxx/CVE-2025-35939.json

GitHub Advisory Database

Also known as / affected packages

Defensive techniques (MITRE D3FEND)

D3FEND maps these defensive techniques to the weakness (CWE) that NVD lists for this CVE, through the digital artifacts the weakness affects. D3FEND does not say they stop this vulnerability.

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