CVE-2026-21725: Authorization Bypass via TOCTOU in Grafana Datasource Deletion by Name

Vulnerability summary

CVE-2026-21725 is a low (CVSS 2.6) vulnerability in grafana. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 8% of scored vulnerabilities.

Timeline

1. 25-02-2026
   PublishedVulnerability first disclosed.
2. 27-08-2026
   Last modifiedVulnerability information updated.

Description

A time-of-create-to-time-of-use (TOCTOU) vulnerability lets recently deleted-then-recreated data sources be re-deleted without permission to do so. This requires several very stringent conditions to be met: - The attacker must have admin access to the specific datasource prior to its first deletion. - Upon deletion, all steps within the attack must happen within the next 30 seconds and on the same pod of Grafana. - The attacker must delete the datasource, then someone must recreate it. - The new datasource must not have the attacker as an admin. - The new datasource must have the same UID as the prior datasource. These are randomised by default. - The datasource can now be re-deleted by the attacker. - Once 30 seconds are up, the attack is spent and cannot be repeated. - No datasource with any other UID can be attacked.

• CWE-367Time-of-check Time-of-use (TOCTOU) Race ConditionThe product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.