CVE-2025-35939 Craft CMS Craft CMS: software flaw
In plain words: A mistake in the software that attackers have found a way to abuse. Depends on the product — see the description and the vendor advisory.
Confirmed exploited by CISA on · US federal patch deadline Jun 23, 2025
What to do
- Install Craft CMS's security update for Craft CMS. If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Keep a list of every internet-facing server you run so nothing is forgotten.
- Patch anything in this catalog first, ahead of normal patch cycles.
- Put admin and file-transfer apps behind a VPN or single sign-on instead of the open internet.
Who is affected
Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.
What's at risk: Mass data theft and ransomware: a single flaw in a file-transfer or email server has exposed thousands of organisations at once.
The details
- Official name
- Craft CMS External Control of Assumed-Immutable Web Parameter Vulnerability
- Product
- Craft CMS Craft CMS
- CISA description
- 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.
- Type of flaw
- Software flaw (CWE-472)
- Confirmed exploited
- Jun 2, 2025
- US federal patch deadline
- Jun 23, 2025
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Answering about CVE-2025-35939 ·
Questions about CVE-2025-35939
Is CVE-2025-35939 being exploited?
Yes. CISA added CVE-2025-35939 to its Known Exploited Vulnerabilities catalog on Jun 2, 2025, which means there is reliable evidence of real-world attacks.
How do I fix CVE-2025-35939?
Install Craft CMS's security update for Craft CMS. If no update exists, follow the vendor's workaround or stop using the product until one ships. Keep a list of every internet-facing server you run so nothing is forgotten.
Am I affected by CVE-2025-35939?
Only if you use Craft CMS Craft CMS. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.