{"id":"GHSA-497x-rrr9-68jp","summary":"Grafana Loki Path Traversal - CVE-2021-36156 Bypass","details":"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}\n\nThanks to Prasanth Sundararajan for reporting this vulnerability.","aliases":["CVE-2026-21726","GO-2026-5115"],"modified":"2026-09-10T03:51:00.938890119Z","published":"2026-04-15T21:30:18Z","database_specific":{"cwe_ids":["CWE-22","CWE-601"],"severity":"MODERATE","github_reviewed":true,"github_reviewed_at":"2026-04-16T21:42:00Z","nvd_published_at":"2026-04-15T20:16:34Z"},"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-21726"},{"type":"PACKAGE","url":"https://github.com/grafana/loki"},{"type":"WEB","url":"https://grafana.com/security/security-advisories/cve-2026-21726"}],"affected":[{"package":{"name":"github.com/grafana/loki/v3","ecosystem":"Go","purl":"pkg:golang/github.com/grafana/loki/v3"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.6.4"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-497x-rrr9-68jp/GHSA-497x-rrr9-68jp.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"}]}