CVE-2026-27127: Craft CMS has Cloud Metadata SSRF Protection Bypass via DNS Rebinding
(updated )
The SSRF validation in Craft CMS’s GraphQL Asset mutation performs DNS resolution separately from the HTTP request. This Time-of-Check-Time-of-Use (TOCTOU) vulnerability enables DNS rebinding attacks, where an attacker’s DNS server returns different IP addresses for validation compared to the actual request.
This is a bypass of the security fix for CVE-2025-68437 (GHSA-x27p-wfqw-hfcc) that allows access to all blocked IPs, not just IPv6 endpoints.
References
- curl.se/libcurl/c/CURLOPT_RESOLVE.html
- github.com/advisories/GHSA-gp2f-7wcm-5fhx
- github.com/craftcms/cms
- github.com/craftcms/cms/commit/a4cf3fb63bba3249cf1e2882b18a2d29e77a8575
- github.com/craftcms/cms/security/advisories/GHSA-gp2f-7wcm-5fhx
- github.com/craftcms/cms/security/advisories/GHSA-x27p-wfqw-hfcc
- github.com/mogwailabs/DNSrebinder
- github.com/nccgroup/singularity
- github.com/taviso/rbndr
- nvd.nist.gov/vuln/detail/CVE-2026-27127
- unit42.paloaltonetworks.com/dns-rebinding
Code Behaviors & Features
Detect and mitigate CVE-2026-27127 with GitLab Dependency Scanning
Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Dependency Scanning using SBOM also detects vulnerabilities from proprietary advisories that this site does not include. Learn more about Dependency Scanning using SBOM →