Craft CMS up to 5.8.21 filter_var server-side request forgery

Summaryinfo

A vulnerability was found in Craft CMS up to 5.8.21. It has been declared as critical. Affected is the function filter_var. The manipulation results in server-side request forgery. This vulnerability is identified as CVE-2026-25494. The attack can be executed remotely. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Craft CMS up to 5.8.21. Affected is the function filter_var. The manipulation with an unknown input leads to a server-side request forgery vulnerability. CWE is classifying the issue as CWE-918. The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

Craft is a platform for creating digital experiences. In Craft versions 4.0.0-RC1 through 4.16.17 and 5.0.0-RC1 through 5.8.21, the saveAsset GraphQL mutation uses filter_var(..., FILTER_VALIDATE_IP) to block a specific list of IP addresses. However, alternative IP notations (hexadecimal, mixed) are not recognized by this function, allowing attackers to bypass the blocklist and access cloud metadata services. This issue is patched in versions 4.16.18 and 5.8.22.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-25494 since 02/02/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available.

Upgrading to version 5.8.22 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch d49e93e5ba0c48939ce5eaa6cd9b4a990542d8b2 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Content Management System

Vendor

• Craft

Name

• CMS

Version

• 5.8.0
• 5.8.1
• 5.8.2
• 5.8.3
• 5.8.4
• 5.8.5
• 5.8.6
• 5.8.7
• 5.8.8
• 5.8.9
• 5.8.10
• 5.8.11
• 5.8.12
• 5.8.13
• 5.8.14
• 5.8.15
• 5.8.16
• 5.8.17
• 5.8.18
• 5.8.19
• 5.8.20
• 5.8.21

License

• free

CPE 2.3info

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CPE 2.2info

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Once again VulDB remains the best source for vulnerability data.

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