SAML assertion replay via skipped InResponseTo validation
Medium
| Advisory ID: | CVE-2026-12704 |
| Published: | 2026-09-02 |
| Product: | Grafana Enterprise |
| CVSS Score: | 6.8 |
| CVSS Vector: | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N |
| Fixed Versions: | <11.6.0 >=12.4.11 <13.0.0 >=13.0.8 <13.1.0 >=13.1.5 <13.2.0 >=13.2.1 |
Summary
When SAML IdP-initiated login is enabled in Grafana Enterprise, the SAML library skips validation of the InResponseTo field on all SAML responses, including SP-initiated logins. This removes anti-replay protection, allowing an attacker who obtains a valid signed SAML assertion to replay it and gain a session as the victim user. Only instances with the allow_idp_initiated SAML setting enabled are affected; this setting is off by default and Grafana OSS is not affected.