{"cve":"CVE-2026-39410","nvd":{"published":"2026-04-08T15:16:15.143","modified":"2026-07-24T21:10:00.143","status":"Analyzed","description":"Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.12, a discrepancy between browser cookie parsing and parse() handling allows cookie prefix protections to be bypassed. Cookie names that are treated as distinct by the browser may be normalized to the same key by parse(), allowing attacker-controlled cookies to override legitimate ones. This vulnerability is fixed in 4.12.12.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","score":4.8},"cwes":["CWE-20"],"references":["https://github.com/honojs/hono/commit/cc067c85592415cb1880ad3c61ed923472452ec0","https://github.com/honojs/hono/releases/tag/v4.12.12","https://github.com/honojs/hono/security/advisories/GHSA-r5rp-j6wh-rvv4"],"products":["hono:hono"],"source":"nvd","synced_at":"2026-10-19T22:28:59.047572785+00:00"},"epss":{"cve":"CVE-2026-39410","score":0.00284,"percentile":0.2094,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-r5rp-j6wh-rvv4","url":"https://osv.dev/vulnerability/GHSA-r5rp-j6wh-rvv4","summary":"Hono: Non-breaking space prefix bypass in cookie name handling in getCookie()","modified":"2026-09-10T03:51:02.862741526Z","packages":[{"ecosystem":"npm","name":"hono","purl":"pkg:npm/hono","ranges":["<4.12.12"],"fixed":["4.12.12"]}]}],"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."]}