{"cve":"CVE-2026-54286","nvd":{"published":"2026-06-22T18:16:47.213","modified":"2026-10-25T23:10:00.167","status":"Deferred","description":"Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.25, on Windows hosts, an encoded backslash (%5C) in the request path decodes to \\, which the Windows path resolver treats as a separator. serve-static then resolves a single URL segment such as admin\\secret.txt into a nested file under the root and serves it, letting an attacker read static files meant to be protected behind prefix-mounted middleware. This vulnerability is fixed in 4.12.25.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","score":5.9},"cwes":["CWE-22"],"references":["https://github.com/honojs/hono/security/advisories/GHSA-wwfh-h76j-fc44"],"products":[],"source":"nvd","synced_at":"2026-10-25T23:44:33.281319194+00:00"},"epss":{"cve":"CVE-2026-54286","score":0.00433,"percentile":0.37321,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-wwfh-h76j-fc44","url":"https://osv.dev/vulnerability/GHSA-wwfh-h76j-fc44","summary":"hono: Path traversal in `serve-static` on Windows via encoded backslash (`%5C`)","modified":"2026-09-10T03:50:51.049920484Z","packages":[{"ecosystem":"npm","name":"hono","purl":"pkg:npm/hono","ranges":["<4.12.25"],"fixed":["4.12.25"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}