{"id":"CVE-2026-86253","state":"PUBLISHED","title":"h3 before 1.15.6 Path Traversal via Percent-Encoded Dot Segments","description":"h3 (npm package) versions <= 2.0.1-rc.14 contain a path traversal vulnerability in serveStatic(). On Node.js deployments, event.url.pathname is not normalized, so percent-encoded dot segments (%2e%2e) are passed to decodeURI() and decoded to ../ sequences without sanitization. An unauthenticated remote attacker can send crafted requests to endpoints served by serveStatic() to read arbitrary files outside the intended static directory. Fixed in 1.15.6 and 2.0.1-rc.15.","publishedAt":"2026-09-06T12:00:28.232Z","updatedAt":"2026-09-10T15:04:40.108Z","severity":{"score":8.2,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","source":"VulnCheck"},"assigner":"VulnCheck","products":["h3js h3"],"affected":[{"vendor":"h3js","product":"h3","packageURL":"pkg:npm/h3","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"1.15.6","versionType":"semver"},{"version":"1.15.6","status":"unaffected","versionType":"semver"},{"version":"2.0.0-beta.0","status":"affected","lessThan":"2.0.1-rc.15","versionType":"semver"},{"version":"2.0.1-rc.15","status":"unaffected","versionType":"semver"}]}],"references":["https://github.com/h3js/h3/security/advisories/GHSA-wr4h-v87w-p3r7","https://www.vulncheck.com/advisories/h3-before-1.15.6-path-traversal-via-percent-encoded-dot-segments"],"weaknesses":["CWE-22"],"ingestedAt":"2026-10-29T20:13:26.108Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/86xxx/CVE-2026-86253.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-86253","state":"PUBLISHED","datePublished":"2026-09-06T12:00:28.232Z","dateUpdated":"2026-09-10T15:04:40.108Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-09-06T11:35:19.316Z"},"containers":{"cna":{"title":"h3 before 1.15.6 Path Traversal via Percent-Encoded Dot Segments","descriptions":[{"lang":"en","value":"h3 (npm package) versions <= 2.0.1-rc.14 contain a path traversal vulnerability in serveStatic(). On Node.js deployments, event.url.pathname is not normalized, so percent-encoded dot segments (%2e%2e) are passed to decodeURI() and decoded to ../ sequences without sanitization. An unauthenticated remote attacker can send crafted requests to endpoints served by serveStatic() to read arbitrary files outside the intended static directory. Fixed in 1.15.6 and 2.0.1-rc.15."}],"affected":[{"vendor":"h3js","product":"h3","packageURL":"pkg:npm/h3","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"1.15.6","versionType":"semver"},{"version":"1.15.6","status":"unaffected","versionType":"semver"},{"version":"2.0.0-beta.0","status":"affected","lessThan":"2.0.1-rc.15","versionType":"semver"},{"version":"2.0.1-rc.15","status":"unaffected","versionType":"semver"}]}],"references":[{"url":"https://github.com/h3js/h3/security/advisories/GHSA-wr4h-v87w-p3r7","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-wr4h-v87w-p3r7)"},{"url":"https://www.vulncheck.com/advisories/h3-before-1.15.6-path-traversal-via-percent-encoded-dot-segments","name":"VulnCheck Advisory: h3 before 1.15.6 Path Traversal via Percent-Encoded Dot Segments","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.2,"baseSeverity":"HIGH"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"NONE","availabilityImpact":"NONE","baseScore":5.9,"baseSeverity":"MEDIUM"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-22","lang":"en","description":"Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-09-06T12:00:28.232Z"},"datePublic":"2026-03-17T00:00:00.000Z","credits":[{"lang":"en","value":"0xkakash1","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-10T14:19:05.242837Z","id":"CVE-2026-86253","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-10T15:04:40.108Z"}}]}}}