#VU122161 Path traversal in Loki - CVE-2026-21726
Published: January 30, 2026
Vulnerability identifier: #VU122161
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-21726
CWE-ID: CWE-22
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Loki
Loki
Software vendor:
Grafana Labs
Grafana Labs
Description
The vulnerability allows a remote attacker to perform directory traversal attacks.
The vulnerability exists due to input validation error when processing directory traversal sequences within the "/loki/api/v1/rules/{namespace}" API endpoint. A remote attacker can send a specially crafted HTTP request and read arbitrary files on the system.
Note, the vulnerability exists due to incomplete fix for #VU64412 (CVE-2021-36156).
Remediation
Install updates from vendor's website.