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.