{"cve":"CVE-2026-69207","nvd":{"published":"2026-08-07T21:17:29.847","modified":"2026-10-24T16:10:00.153","status":"Deferred","description":"Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.34, the built-in CORS middleware, hono/cors, is vulnerable to a regular expression denial of service (ReDoS). During a preflight OPTIONS request, the middleware parses the attacker-controlled Access-Control-Request-Headers header using a whitespace-tolerant regular expression whose backtracking makes its running time quadratic in the input length. Because the header value is bounded only by the deployment's maximum HTTP header size, a single preflight carrying a long run of whitespace can consume seconds of CPU and block request processing. On runtimes that share one execution thread across requests, this stalls concurrent requests as well, and repeated requests can render the service unresponsive. This affects the default configuration, since the vulnerable path is reached whenever cors() is used with an unset or empty allowHeaders. Applications that set a non-empty allowHeaders are not affected. This issue is fixed in version 4.12.34.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","score":5.3},"cwes":["CWE-1333"],"references":["https://github.com/honojs/hono/commit/93fc250d8b4df58ea542cb945171de8013d5e6d5","https://github.com/honojs/hono/releases/tag/v4.12.34","https://github.com/honojs/hono/security/advisories/GHSA-8j4g-w8fx-2239"],"products":[],"source":"nvd","synced_at":"2026-10-24T16:53:34.184483516+00:00"},"epss":{"cve":"CVE-2026-69207","score":0.00609,"percentile":0.48851,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-8j4g-w8fx-2239","url":"https://osv.dev/vulnerability/GHSA-8j4g-w8fx-2239","summary":"Hono: ReDoS in CORS middleware via Access-Control-Request-Headers","modified":"2026-09-10T03:51:13.583285977Z","packages":[{"ecosystem":"npm","name":"hono","purl":"pkg:npm/hono","ranges":["<4.12.34"],"fixed":["4.12.34"]}]}],"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."]}