CVE-2026-27129

The record

Craft is a content management system (CMS). In versions 4.5.0-RC1 through 4.16.18 and 5.0.0-RC1 through 5.8.22, the SSRF validation in Craft CMS’s GraphQL Asset mutation uses `gethostbyname()`, which only resolves IPv4 addresses. When a hostname has only AAAA (IPv6) records, the function returns the hostname string itself, causing the blocklist comparison to always fail and completely bypassing SSRF protection. This is a bypass of the security fix for CVE-2025-68437. Exploitation requires GraphQL schema permissions for editing assets in the `<VolumeName>` volume and creating assets in the `<VolumeName>` volume. These permissions may be granted to authenticated users with appropriate GraphQL schema access and/or Public Schema (if misconfigured with write permissions). Versions 4.16.19 and 5.8.23 patch the issue.

Affected packages

Related vulnerabilities

• GHSA-v2gc-rm6g-wrw9 Craft CMS: Cloud Metadata SSRF Protection Bypass via IPv6 Resolution Same vulnerability
• GHSA-x27p-wfqw-hfcc Craft CMS vulnerable to Server-Side Request Forgery (SSRF) via GraphQL Asset Upload… Same vulnerability
• GHSA-234q-vvw3-mrfq Craft CMS has unauthenticated activation email trigger with potential user enumeration Also affects craftcms/cms
• CVE-2026-29069 Craft is a content management system (CMS). Also affects craftcms/cms
• CVE-2026-28696 Craft is a content management system (CMS). Also affects craftcms/cms
• CVE-2026-28781 Craft is a content management system (CMS). Also affects craftcms/cms
• CVE-2026-28784 Craft is a content management system (CMS). Also affects craftcms/cms
• CVE-2026-28782 Craft is a content management system (CMS). Also affects craftcms/cms