Server-Side Request Forgery (SSRF) in Craft CMS - CVE-2026-27129
Published: April 17, 2026
Vulnerability identifier: #VU126481
CSH Severity: Low
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-27129
CWE-ID: CWE-918
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to disclose sensitive information.
The vulnerability exists due to improper SSRF protection in GraphQL Asset mutation URL validation when resolving hostnames that have only AAAA records. A remote user can send a specially crafted GraphQL asset mutation with a URL that resolves only to an IPv6 address to disclose sensitive information.
Exploitation requires GraphQL schema permissions to create and edit assets, or a public GraphQL schema that is misconfigured with write permissions.
Affected software
Craft CMS
How to mitigate CVE-2026-27129
Install security update from vendor's website.
Craft CMS - addressed in versions 4.16.19, 5.8.23