CVE-2026-21726

Updated on 15 Apr 2026

Severity

5.3 Medium severity

Details

CVSS score
5.3
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Overview

About vulnerability

The CVE-2021-36156 fix validates the namespace parameter for path traversal sequences after a single URL decode, by double encoding, an attacker can read files at the Ruler API endpoint /loki/api/v1/rules/{namespace}

Thanks to Prasanth Sundararajan for reporting this vulnerability.

Details

Affected product:
Grafana , Loki
Affected packages:
Loki @ 3.3.0 (+7 more)

The CVE-2021-36156 fix validates the namespace parameter for path traversal sequences after a single URL decode, by double encoding, an attacker can read files at the Ruler API endpoint /loki/api/v1/rules/{namespace}

Thanks to Prasanth Sundararajan for reporting this vulnerability.

Fixes