CVE-2021-36156

Name: CVE-2021-36156
Creator: NVD / NIST
Published: 2021-08-03T15:15:08.623+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 1.49%

Last modified Jun 17, 2026

CVE-2021-36156 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. An issue was discovered in Grafana Loki through 2.2.1. The header value X-Scope-OrgID is used to construct file paths for rules files, and if crafted to conduct directory traversal such as ae ../../sensitive/path/in/deployment pathname, then Loki will attempt to parse a rules file at that location and include some of the contents in the error message.. EPSS estimates a 1.49% chance of exploitation in the next 30 days.

Description

An issue was discovered in Grafana Loki through 2.2.1. The header value X-Scope-OrgID is used to construct file paths for rules files, and if crafted to conduct directory traversal such as ae ../../sensitive/path/in/deployment pathname, then Loki will attempt to parse a rules file at that location and include some of the contents in the error message.

Metrics

CVSS 3.1

5.3/10

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

EPSS Probability

1.49%

70.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-22

Affected Software

Vendor	Product	Versions
Grafana	Loki	<= 2.2.1

References

https://github.com/grafana/loki/pull/4020#issue-694377133Issue Tracking, Third Party Advisory
https://github.com/grafana/loki/releases/tag/v2.3.0Patch, Third Party Advisory
https://github.com/grafana/loki/pull/4020#issue-694377133Issue Tracking, Third Party Advisory
https://github.com/grafana/loki/releases/tag/v2.3.0Patch, Third Party Advisory

Timeline

Published: Aug 3, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-36156?

How severe is CVE-2021-36156?

CVE-2021-36156 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 1.49% probability of exploitation in the next 30 days.

How do I fix CVE-2021-36156?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-36156?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST