{"api_version":"1","generated_at":"2026-11-13T01:07:57+00:00","cve":"CVE-2026-126357","urls":{"html":"https://cve.report/CVE-2026-126357","api":"https://cve.report/api/cve/CVE-2026-126357.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-126357","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-126357"},"summary":{"title":"Hono: `mount()` and `app.mount()` can forward a path that bypasses middleware scoped inside the mount prefix","description":"Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.13.16, mount() and app.mount() can remove a dynamic mount prefix using the route-pattern length rather than the matched-prefix length, allowing a crafted path to be forwarded as a protected inner route while the outer application routes the original path. Since 4.12.21, rebuilding the forwarded URL from the decoded pathname can also convert a decoded backslash to a slash and collapse parent-directory segments, again causing the mounted application to receive a protected path. An unauthenticated client can use either applicable path transformation to reach a mounted route without authentication or authorization middleware scoped to a subpath inside the mount prefix. This issue is fixed in version 4.13.16.","state":"PUBLISHED","assigner":"GitHub_M","published_at":"2026-11-13 00:20:10","updated_at":"2026-11-13 00:20:11"},"problem_types":["CWE-288","CWE-288 CWE-288: Authentication Bypass Using an Alternate Path or Channel"],"metrics":[{"version":"3.1","source":"security-advisories@github.com","type":"Secondary","score":"5.3","severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","data":{"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","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"NONE","availabilityImpact":"NONE"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"5.3","severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","data":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5.3,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","version":"3.1"}}],"references":[{"url":"https://github.com/honojs/hono/releases/tag/v4.13.16","name":"https://github.com/honojs/hono/releases/tag/v4.13.16","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/honojs/hono/commit/34f90432a1794b28e52802670efcd01963f716d6","name":"https://github.com/honojs/hono/commit/34f90432a1794b28e52802670efcd01963f716d6","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/honojs/hono/security/advisories/GHSA-4m76-xfj5-7975","name":"https://github.com/honojs/hono/security/advisories/GHSA-4m76-xfj5-7975","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-126357","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-126357","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"honojs","product":"hono","version":"affected < 4.13.16","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"product":"hono","vendor":"honojs","versions":[{"status":"affected","version":"< 4.13.16"}]}],"descriptions":[{"lang":"en","value":"Hono is a Web application framework that provides support for any JavaScript runtime. 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This issue is fixed in version 4.13.16."}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5.3,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-288","description":"CWE-288: Authentication Bypass Using an Alternate Path or Channel","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-11-12T22:18:46.437Z","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M"},"references":[{"name":"https://github.com/honojs/hono/security/advisories/GHSA-4m76-xfj5-7975","tags":["x_refsource_CONFIRM"],"url":"https://github.com/honojs/hono/security/advisories/GHSA-4m76-xfj5-7975"},{"name":"https://github.com/honojs/hono/commit/34f90432a1794b28e52802670efcd01963f716d6","tags":["x_refsource_MISC"],"url":"https://github.com/honojs/hono/commit/34f90432a1794b28e52802670efcd01963f716d6"},{"name":"https://github.com/honojs/hono/releases/tag/v4.13.16","tags":["x_refsource_MISC"],"url":"https://github.com/honojs/hono/releases/tag/v4.13.16"}],"source":{"advisory":"GHSA-4m76-xfj5-7975","discovery":"UNKNOWN"},"title":"Hono: `mount()` and `app.mount()` can forward a path that bypasses middleware scoped inside the mount prefix"}},"cveMetadata":{"assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","assignerShortName":"GitHub_M","cveId":"CVE-2026-126357","datePublished":"2026-11-12T22:18:46.437Z","dateReserved":"2026-11-10T21:12:01.227Z","dateUpdated":"2026-11-12T22:18:46.437Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-11-13 00:20:10","lastModifiedDate":"2026-11-13 00:20:11","problem_types":["CWE-288","CWE-288 CWE-288: Authentication Bypass Using an Alternate Path or Channel"],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"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","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"NONE","availabilityImpact":"NONE"},"exploitabilityScore":3.9,"impactScore":1.4}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"126357","Ordinal":"1","Title":"Hono: `mount()` and `app.mount()` can forward a path that bypass","CVE":"CVE-2026-126357","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"126357","Ordinal":"1","NoteData":"Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.13.16, mount() and app.mount() can remove a dynamic mount prefix using the route-pattern length rather than the matched-prefix length, allowing a crafted path to be forwarded as a protected inner route while the outer application routes the original path. Since 4.12.21, rebuilding the forwarded URL from the decoded pathname can also convert a decoded backslash to a slash and collapse parent-directory segments, again causing the mounted application to receive a protected path. An unauthenticated client can use either applicable path transformation to reach a mounted route without authentication or authorization middleware scoped to a subpath inside the mount prefix. This issue is fixed in version 4.13.16.","Type":"Description","Title":"Hono: `mount()` and `app.mount()` can forward a path that bypass"}]}}}