SSRF in Craftcms Cms
CVE-2026-27129
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.
Vulnerability class: SSRF (Server-Side Request Forgery)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (33.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 34th percentile — 33.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: -0.000
Affected products
- Craftcms Cms — versions >= 4.5.0-RC1, < 4.16.19, >= 5.0.0-RC1, < 5.8.23
- Craftcms Craft Cms — versions 5.0.0
Weakness classification (CWE)
References
- github.com/craftcms/cms/security/advisories/GHSA-v2gc-rm6g-wrw9 (Exploit, Patch, Mitigation, Vendor Advisory)
- github.com/craftcms/cms/security/advisories/GHSA-x27p-wfqw-hfcc (Not Applicable)
- github.com/craftcms/cms/commit/2825388b4f32fb1c9bd709027a1a1fd192d709a3 (Patch)
Frequently asked questions
- What is CVE-2026-27129?
- CVE-2026-27129 is a medium-severity vulnerability in Craftcms Cms, classified under Server-Side Request Forgery (SSRF). CVSS score: 6.5/10. Published 2026-02-24.
- How severe is CVE-2026-27129?
- Medium severity. CVSS v3 base score is 6.5 out of 10.