CVE-2026-21725: Grafana Privilege Escalation Vulnerability

CVE-2026-21725 Overview

A time-of-create-to-time-of-use (TOCTOU) race condition vulnerability has been identified in Grafana that allows attackers to delete recently recreated data sources without proper authorization. This vulnerability exploits a narrow timing window during datasource recreation, enabling an attacker who previously had admin access to a deleted datasource to re-delete its replacement under specific conditions.

Critical Impact

An attacker with prior admin access to a specific datasource can exploit a 30-second race condition window to delete a newly recreated datasource without current authorization, potentially disrupting monitoring and observability infrastructure.

Affected Products

• Grafana (specific versions not specified in advisory)

Discovery Timeline

• 2026-02-25 - CVE CVE-2026-21725 published to NVD
• 2026-02-25 - Last updated in NVD database

Technical Details for CVE-2026-21725

Vulnerability Analysis

This vulnerability represents a Time-of-Check Time-of-Use (TOCTOU) race condition in Grafana's datasource management functionality. The flaw exists in how Grafana handles authorization checks for datasource operations during a brief window after deletion and recreation. When a datasource is deleted and subsequently recreated with the same UID, Grafana fails to properly invalidate cached authorization states within a 30-second window on the same pod.

The vulnerability requires an attacker who previously held admin privileges on a datasource to exploit a narrow timing window. During this window, authorization decisions may reference stale credentials, allowing the former admin to perform deletion operations on the newly created datasource despite lacking current permissions.

Root Cause

The root cause lies in Grafana's authorization caching mechanism for datasource operations. When a datasource is deleted, the authorization state for that specific UID is not immediately invalidated across all components. If a new datasource is created with the same UID within 30 seconds and on the same Grafana pod, the previous authorization grants may still be cached and honored, creating a race condition that bypasses proper permission checks.

Attack Vector

The attack requires several stringent conditions to be met:

1. The attacker must have had admin access to the specific datasource prior to its first deletion
2. The attacker must delete the datasource, then wait for someone else to recreate it
3. The new datasource must have the same UID as the prior datasource (randomized by default)
4. All attack steps must occur within 30 seconds on the same Grafana pod
5. The new datasource must not have the attacker as an admin
6. Once the 30-second window expires, the attack opportunity is lost
7. Only datasources with matching UIDs are vulnerable; other UIDs cannot be targeted

This represents a network-accessible attack vector requiring low privileges and user interaction, with high attack complexity due to the timing constraints.

Detection Methods for CVE-2026-21725

Indicators of Compromise

• Unexpected datasource deletions occurring within 30 seconds of datasource recreation events
• Audit log entries showing datasource deletion by users who lack current admin permissions
• Sequential delete-create-delete patterns for datasources with identical UIDs
• Authorization anomalies where former datasource admins appear to retain access after permission revocation

Detection Strategies

• Monitor Grafana audit logs for datasource deletion events and correlate with current permission states
• Implement alerting for rapid delete-create-delete sequences on datasources within 30-second windows
• Review access control logs for datasource operations performed by users without current admin privileges
• Deploy network monitoring to identify suspicious API call patterns targeting datasource endpoints

Monitoring Recommendations

• Enable comprehensive audit logging for all datasource CRUD operations in Grafana
• Configure alerts for datasource UID reuse events to detect potential exploitation attempts
• Implement real-time monitoring of Grafana pod activity for authorization anomalies
• Review Grafana access logs regularly for patterns indicating exploitation of the race condition

How to Mitigate CVE-2026-21725

Immediate Actions Required

• Review recent datasource deletion activities in Grafana audit logs for suspicious patterns
• Implement unique UID policies to prevent datasource UID reuse during recreation
• Consider deploying Grafana in configurations that minimize same-pod request routing
• Monitor for any signs of unauthorized datasource modifications in production environments

Patch Information

Refer to the Grafana Security Advisory CVE-2026-21725 for official patch information and recommended remediation steps. Organizations should update to the latest patched version of Grafana as recommended by the vendor.

Workarounds

• Implement organizational policies to always use unique UIDs when recreating datasources
• Configure Grafana deployments to use random UID generation (default behavior) and enforce this at the administrative level
• Increase monitoring during datasource lifecycle operations to detect potential abuse
• Consider implementing additional authorization checks at the network or proxy layer for datasource deletion operations

# Configuration example
# Ensure unique UID generation for datasources in Grafana provisioning
# grafana.ini configuration to enhance datasource security

[security]
# Enable strict permission checking
disable_gravatar = true

[datasources]
# Log all datasource operations for audit
# Monitor via external logging aggregation

# Review datasource provisioning files to ensure unique UIDs
# Example: /etc/grafana/provisioning/datasources/datasources.yaml
# Each datasource should have a unique, randomly generated UID