{"id":"CVE-2026-21726","state":"PUBLISHED","title":"Loki Path Traversal - CVE-2021-36156 Bypass","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}\n\nThanks to Prasanth Sundararajan for reporting this vulnerability.","publishedAt":"2026-04-15T19:24:31.268Z","updatedAt":"2026-08-27T17:22:30.899Z","severity":{"score":5.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","source":"GRAFANA"},"assigner":"GRAFANA","products":["Grafana Loki"],"affected":[{"vendor":"Grafana","product":"Loki","defaultStatus":"unaffected","versions":[{"version":"2.3.0","status":"affected","lessThan":"3.5.9","versionType":"semver"}]}],"references":["https://grafana.com/security/security-advisories/cve-2026-21726"],"weaknesses":["CWE-22"],"ingestedAt":"2026-10-29T20:11:10.572Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/21xxx/CVE-2026-21726.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-21726","state":"PUBLISHED","datePublished":"2026-04-15T19:24:31.268Z","dateUpdated":"2026-08-27T17:22:30.899Z","assignerShortName":"GRAFANA","assignerOrgId":"57da9224-a3e2-4646-9d0e-c4dc2e05e7da","dateReserved":"2026-01-05T09:26:06.215Z"},"containers":{"cna":{"title":"Loki Path Traversal - CVE-2021-36156 Bypass","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Grafana","product":"Loki","defaultStatus":"unaffected","versions":[{"version":"2.3.0","status":"affected","lessThan":"3.5.9","versionType":"semver"}]}],"references":[{"url":"https://grafana.com/security/security-advisories/cve-2026-21726","tags":["vendor-advisory"]}],"metrics":[{"cvssV3_1":{"version":"3.1","baseScore":5.3,"baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"}}],"providerMetadata":{"shortName":"GRAFANA","orgId":"57da9224-a3e2-4646-9d0e-c4dc2e05e7da","dateUpdated":"2026-08-27T17:22:30.899Z"},"datePublic":"2026-04-15T19:20:00.780Z","source":{"discovery":"BUG_BOUNTY"},"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-15T20:01:24.769436Z","id":"CVE-2026-21726","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-22","type":"CWE","lang":"en","description":"CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-04-20T18:58:17.749Z"}}]}}}