GitHub Advisoryadvisory · Go

GHSA-497x-rrr9-68jp Grafana Loki Path Traversal - CVE-2021-36156 Bypass

MEDIUM Published 2026-04-15 Modified 2026-04-16 Official page ↗
Aliases
CVE-2026-21726
Ecosystem
Go
Packages
github.com/grafana/loki/v3
Severity
Moderate
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Weaknesses
CWE-22, CWE-601
Reviewed
2026-04-16

Affected packages

• Go github.com/grafana/loki/v3: < 3.6.4 → fixed in 3.6.4

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.

Related

Alias · CVE (1)

  • CVE-2026-21726 The CVE-2021-36156 fix validates the namespace parameter for path traversal sequences after a single URL decode, by double encoding, an… vulnerability

Weakness · CWE (2)

  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory weakness
  • CWE-601 URL Redirection to Untrusted Site weakness

References