CVE-2026-21726
Grafana Loki Path Traversal - CVE-2021-36156 Bypass
5.3
MEDIUM
CVSS 3.1
EPSS 0.02%
Description
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.
How to fix CVE-2026-21726
To remediate CVE-2026-21726, upgrade the affected package to a fixed version below.
- —upgrade to 3.6.4 or later
Is CVE-2026-21726 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 3.6.4
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |