{"schema_version":"1.7.5","id":"GHSA-37ch-88jc-xwx2","published":"2026-03-27T20:04:53Z","modified":"2026-07-08T08:11:17.227452935Z","aliases":["CVE-2024-45296","CVE-2026-4867","GHSA-9wv6-86v2-598j"],"related":["CGA-8j86-34gg-44ch"],"summary":"path-to-regexp vulnerable to Regular Expression Denial of Service via multiple route parameters","details":"### Impact\n\nA bad regular expression is generated any time you have three or more parameters within a single segment, separated by something that is not a period (`.`). For example, `/:a-:b-:c` or `/:a-:b-:c-:d`. The backtrack protection added in `path-to-regexp@0.1.12` only prevents ambiguity for two parameters. With three or more, the generated lookahead does not block single separator characters, so capture groups overlap and cause catastrophic backtracking.\n\n### Patches\n\nUpgrade to [path-to-regexp@0.1.13](https://github.com/pillarjs/path-to-regexp/releases/tag/v.0.1.13)\n\nCustom regex patterns in route definitions (e.g., `/:a-:b([^-/]+)-:c([^-/]+)`) are not affected because they override the default capture group.\n\n### Workarounds\n\nAll versions can be patched by providing a custom regular expression for parameters after the first in a single segment. As long as the custom regular expression does not match the text before the parameter, you will be safe. For example, change `/:a-:b-:c` to `/:a-:b([^-/]+)-:c([^-/]+)`.\n\nIf paths cannot be rewritten and versions cannot be upgraded, another alternative is to limit the URL length.\n\n### References\n\n- [GHSA-9wv6-86v2-598j](https://github.com/advisories/GHSA-9wv6-86v2-598j)\n- [Detailed blog post: ReDoS the web](https://blakeembrey.com/posts/2024-09-web-redos/)","affected":[{"package":{"name":"path-to-regexp","ecosystem":"npm","purl":"pkg:npm/path-to-regexp"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.1.13"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-37ch-88jc-xwx2/GHSA-37ch-88jc-xwx2.json"}}],"references":[{"type":"WEB","url":"https://github.com/pillarjs/path-to-regexp/security/advisories/GHSA-37ch-88jc-xwx2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-4867"},{"type":"WEB","url":"https://blakeembrey.com/posts/2024-09-web-redos"},{"type":"WEB","url":"https://cna.openjsf.org/security-advisories.html"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-9wv6-86v2-598j"},{"type":"PACKAGE","url":"https://github.com/pillarjs/path-to-regexp"},{"type":"WEB","url":"https://github.com/pillarjs/path-to-regexp/releases/tag/v.0.1.13"}],"database_specific":{"cwe_ids":["CWE-1333"],"github_reviewed":true,"github_reviewed_at":"2026-03-27T20:04:53Z","nvd_published_at":"2026-03-26T17:16:42Z","severity":"HIGH"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}