{"id":"CVE-2026-90982","state":"PUBLISHED","title":"@fastify/static vulnerable to route guard bypass via path case-folding","description":"@fastify/static is a Fastify plugin that serves static files from a configured root directory. In versions before 10.1.4, on a case-insensitive filesystem such as Windows or the default macOS volume, a route guard or allowedPath restriction can be bypassed by altering the letter case of a path segment. The route matcher is case-sensitive while the filesystem is not, so a request that changes the case of a protected segment does not match the guarded route and falls through to the static handler, yet the filesystem resolves it to the same protected file. As a result, an unauthenticated request can read a file that a route guard or allowedPath was configured to protect. The issue does not affect case-sensitive filesystems and is not a directory traversal, since nothing is served from outside the configured root. The issue is fixed in @fastify/static 10.1.4, which validates the requested path against its actual on-disk spelling and rejects case-aliased paths before authorization. As a workaround, serve static files from a case-sensitive filesystem, or ensure route guards and allowedPath rules account for every letter-case variant of the protected paths.","publishedAt":"2026-09-17T06:55:42.300Z","updatedAt":"2026-09-17T12:33:23.661Z","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":"openjs"},"assigner":"openjs","products":["@fastify/static @fastify/static"],"affected":[{"vendor":"@fastify/static","product":"@fastify/static","packageURL":"pkg:npm/@fastify/static","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"10.1.4","versionType":"semver"},{"version":"10.1.4","status":"unaffected","versionType":"semver"}]}],"references":["https://github.com/fastify/fastify-static/security/advisories/GHSA-r799-r9gc-m956","https://cna.openjsf.org/security-advisories.html"],"weaknesses":["CWE-178","CWE-284"],"ingestedAt":"2026-10-29T20:13:34.582Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/90xxx/CVE-2026-90982.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-90982","state":"PUBLISHED","datePublished":"2026-09-17T06:55:42.300Z","dateUpdated":"2026-09-17T12:33:23.661Z","assignerShortName":"openjs","assignerOrgId":"ce714d77-add3-4f53-aff5-83d477b104bb","dateReserved":"2026-09-14T13:46:58.766Z"},"containers":{"cna":{"title":"@fastify/static vulnerable to route guard bypass via path case-folding","descriptions":[{"lang":"en","value":"@fastify/static is a Fastify plugin that serves static files from a configured root directory. In versions before 10.1.4, on a case-insensitive filesystem such as Windows or the default macOS volume, a route guard or allowedPath restriction can be bypassed by altering the letter case of a path segment. The route matcher is case-sensitive while the filesystem is not, so a request that changes the case of a protected segment does not match the guarded route and falls through to the static handler, yet the filesystem resolves it to the same protected file. As a result, an unauthenticated request can read a file that a route guard or allowedPath was configured to protect. The issue does not affect case-sensitive filesystems and is not a directory traversal, since nothing is served from outside the configured root. The issue is fixed in @fastify/static 10.1.4, which validates the requested path against its actual on-disk spelling and rejects case-aliased paths before authorization. As a workaround, serve static files from a case-sensitive filesystem, or ensure route guards and allowedPath rules account for every letter-case variant of the protected paths."}],"affected":[{"vendor":"@fastify/static","product":"@fastify/static","packageURL":"pkg:npm/@fastify/static","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"10.1.4","versionType":"semver"},{"version":"10.1.4","status":"unaffected","versionType":"semver"}]}],"references":[{"url":"https://github.com/fastify/fastify-static/security/advisories/GHSA-r799-r9gc-m956"},{"url":"https://cna.openjsf.org/security-advisories.html"}],"metrics":[{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","baseScore":5.3,"baseSeverity":"MEDIUM"},"scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-178","lang":"en","description":"CWE-178: Improper Handling of Case Sensitivity","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-284","lang":"en","description":"CWE-284: Improper Access Control","type":"CWE"}]}],"providerMetadata":{"shortName":"openjs","orgId":"ce714d77-add3-4f53-aff5-83d477b104bb","dateUpdated":"2026-09-17T06:55:42.300Z"},"credits":[{"lang":"en","type":"reporter","value":"0xRenSec"},{"lang":"en","type":"remediation developer","value":"mcollina"},{"lang":"en","type":"remediation reviewer","value":"UlisesGascon"}],"x_generator":{"engine":"cve-kit 1.0.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-17T12:32:46.853799Z","id":"CVE-2026-90982","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-17T12:33:23.661Z"}}]}}}