CVE-2026-21726
Medium
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.
SeverityMedium
CVSS5.3
Exploit probability—
Product
Grafana Loki
PublishedApr 15, 2026
First seenApr 15, 2026
Weakness typeCWE-22Path traversal
How to fix
Update
- grafana loki3.6.4 or later
- github.com/grafana/loki/v33.6.4 or later
Vendor advisories
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| grafana loki | v < 3.6.4 | 3.6.4 |
| github.com/grafana/loki/v3Go | v < 3.6.4 | 3.6.4 |
| github.com/grafana/lokiGo | No range specified | — |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
In the Intelligence 360 plan
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.