{"id":"CVE-2026-4867","aliases":["CLSA-2026-1777250311","CLSA-2026-1779238048","CLSA-2026-1792663862","CLSA-2026-1792789806","DEBIAN-CVE-2026-4867","EUVD-2026-16273","GHSA-37ch-88jc-xwx2","GHSA-9wv6-86v2-598j","ROOT-APP-NPM-CVE-2026-4867","UBUNTU-CVE-2026-4867"],"status":"published","title":"path-to-regexp vulnerable to Regular Expression Denial of Service via multiple route parameters","description":"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\nPatches:\n\nUpgrade to path-to-regexp@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\nWorkarounds:\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.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00515,"percentile":0.4417,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-1333"],"published":"2024-09-09T19:07:40.313Z","modified":"2026-10-28T02:30:52Z","fixes":[{"ecosystem":"npm","package":"path-to-regexp","fixed_in":["0.1.13"],"sources":["ghsa"]},{"ecosystem":"TuxCare:npm","package":"path-to-regexp","fixed_in":["0.1.3-tuxcare.2","0.1.12-tuxcare.1","0.1.7-tuxcare.2","0.1.10-tuxcare.3"],"sources":["osv"]},{"ecosystem":"Debian:12","package":"node-path-to-regexp","fixed_in":["1.0.1-1"],"sources":["osv"]},{"ecosystem":"Debian:13","package":"node-path-to-regexp","fixed_in":["1.0.1-1"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"node-path-to-regexp","fixed_in":["1.0.1-1"],"sources":["osv"]},{"ecosystem":"Root:npm","package":"@rootio/path-to-regexp","fixed_in":["0.1.12-root.io.1","0.1.12-root.io.2","0.1.10-root.io.2","0.1.10-root.io.1","0.1.10-root.io.3"],"sources":["osv"]},{"ecosystem":"Root:npm","package":"path-to-regexp","fixed_in":["0.1.12-aikido.2","0.1.10-aikido.2","0.1.10-aikido.1","0.1.10-aikido.3"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"path-to-regexp","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.1.13"}]}]},{"source":"osv","ecosystem":"TuxCare:npm","package":"path-to-regexp","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.1.3-tuxcare.0"},{"fixed":"0.1.3-tuxcare.2"}]}],"versions":["0.1.3","0.1.3-tuxcare.1"]},{"source":"osv","ecosystem":"TuxCare:npm","package":"path-to-regexp","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.1.12-tuxcare.0"},{"fixed":"0.1.12-tuxcare.1"}]}],"versions":["0.1.12"]},{"source":"osv","ecosystem":"TuxCare:npm","package":"path-to-regexp","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.1.7-tuxcare.0"},{"fixed":"0.1.7-tuxcare.2"}]}],"versions":["0.1.7","0.1.7-tuxcare.1"]},{"source":"osv","ecosystem":"TuxCare:npm","package":"path-to-regexp","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.1.10-tuxcare.0"},{"fixed":"0.1.10-tuxcare.3"}]}],"versions":["0.1.10","0.1.10-tuxcare.1","0.1.10-tuxcare.2"]},{"source":"osv","ecosystem":"Debian:12","package":"node-path-to-regexp","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.0.1-1"}]}]},{"source":"osv","ecosystem":"Debian:13","package":"node-path-to-regexp","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.0.1-1"}]}]},{"source":"osv","ecosystem":"Debian:14","package":"node-path-to-regexp","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.0.1-1"}]}]},{"source":"osv","ecosystem":"npm","package":"path-to-regexp","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.1.13"}]}],"bundled":2},{"source":"osv","ecosystem":"npm","package":"path-to-regexp","ranges":[{"type":"SEMVER","events":[{"introduced":"0.2.0"},{"fixed":"1.9.0"}]}],"bundled":2},{"source":"osv","ecosystem":"npm","package":"path-to-regexp","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.1.10"}]}],"bundled":2},{"source":"osv","ecosystem":"npm","package":"path-to-regexp","ranges":[{"type":"SEMVER","events":[{"introduced":"7.0.0"},{"fixed":"8.0.0"}]}],"bundled":2},{"source":"osv","ecosystem":"npm","package":"path-to-regexp","ranges":[{"type":"SEMVER","events":[{"introduced":"2.0.0"},{"fixed":"3.3.0"}]}],"bundled":2},{"source":"osv","ecosystem":"npm","package":"path-to-regexp","ranges":[{"type":"SEMVER","events":[{"introduced":"4.0.0"},{"fixed":"6.3.0"}]}],"bundled":2},{"source":"osv","ecosystem":"Root:npm","package":"@rootio/path-to-regexp","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.1.12-root.io.1"},{"fixed":"0.1.12-root.io.2"},{"fixed":"0.1.10-root.io.2"},{"fixed":"0.1.10-root.io.1"},{"fixed":"0.1.10-root.io.3"}]}]},{"source":"osv","ecosystem":"Root:npm","package":"path-to-regexp","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.1.12-aikido.2"},{"fixed":"0.1.10-aikido.2"},{"fixed":"0.1.10-aikido.1"},{"fixed":"0.1.10-aikido.3"}]}]}],"products":[{"vendor":"path-to-regexp","product":"path-to-regexp"},{"vendor":"pillarjs","product":"path-to-regexp"}],"references":[{"url":"https://github.com/advisories/GHSA-9wv6-86v2-598j","tags":["Not Applicable","advisory","report"]},{"url":"https://blakeembrey.com/posts/2024-09-web-redos","tags":["Technical Description","web","report"]},{"url":"https://cna.openjsf.org/security-advisories.html","tags":["Third Party Advisory","advisory","web","report"]},{"url":"https://github.com/pillarjs/path-to-regexp/security/advisories/GHSA-37ch-88jc-xwx2","tags":["web","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-4867","tags":["advisory"]},{"url":"https://github.com/pillarjs/path-to-regexp/releases/tag/v.0.1.13","tags":["web"]},{"url":"https://github.com/advisories/GHSA-37ch-88jc-xwx2"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/45xxx/CVE-2024-45296.json","tags":["advisory"]},{"url":"https://github.com/pillarjs/path-to-regexp/security/advisories/GHSA-9wv6-86v2-598j","tags":["advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2024-45296","tags":["advisory"]},{"url":"https://security.netapp.com/advisory/ntap-20250124-0001/","tags":["advisory"]},{"url":"https://github.com/pillarjs/path-to-regexp/commit/29b96b4a1de52824e1ca0f49a701183cc4ed476f","tags":["fix","web"]},{"url":"https://github.com/pillarjs/path-to-regexp/commit/60f2121e9b66b7b622cc01080df0aabda9eedee6","tags":["fix","web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/4xxx/CVE-2026-4867.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-4867","tags":["advisory"]},{"url":"https://github.com/pillarjs/path-to-regexp","tags":["package"]},{"url":"https://github.com/pillarjs/path-to-regexp/commit/925ac8e3c5780b02f58cbd4e52f95da8ad2ac485","tags":["web"]},{"url":"https://github.com/pillarjs/path-to-regexp/commit/d31670ae8f6e69cbfd56e835742195b7d10942ef","tags":["web"]},{"url":"https://github.com/pillarjs/path-to-regexp/commit/f1253b47b347dcb909e3e80b0eb2649109e59894","tags":["web"]},{"url":"https://github.com/pillarjs/path-to-regexp/releases/tag/v6.3.0","tags":["web"]},{"url":"https://security.netapp.com/advisory/ntap-20250124-0001","tags":["web"]},{"url":"https://ubuntu.com/security/CVE-2026-4867","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-4867","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-4867","title":"path-to-regexp vulnerable to Regular Expression Denial of Service via multiple route parameters","description":"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\nPatches:\n\nUpgrade to path-to-regexp@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\nWorkarounds:\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.","status":"published","published":"2026-03-26T16:16:25.501Z","modified":"2026-03-26T16:52:14.893Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-1333"],"updated_at":"2026-11-02T14:19:59.369956Z"}],"euvd":[{"id":"EUVD-2026-16273","description":"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\nPatches:\n\nUpgrade to path-to-regexp@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\nWorkarounds:\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.","status":"published","published":"2026-03-26T16:16:25Z","modified":"2026-03-26T16:52:14Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T19:25:28.18595Z"}],"ghsa":[{"id":"GHSA-37ch-88jc-xwx2","title":"path-to-regexp vulnerable to Regular Expression Denial of Service via multiple route parameters","description":"### 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/)","status":"published","published":"2026-03-27T20:04:53Z","modified":"2026-03-27T20:04:54Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-1333"],"updated_at":"2026-11-02T14:39:43.747579Z"}],"nvd":[{"id":"CVE-2026-4867","description":"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\nPatches:\n\nUpgrade to path-to-regexp@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\nWorkarounds:\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.","status":"published","published":"2026-03-26T17:16:42.983Z","modified":"2026-06-17T10:57:21.827Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-1333"],"updated_at":"2026-11-02T14:12:11.678711Z"}],"osv":[{"id":"CVE-2024-45296","title":"path-to-regexp outputs backtracking regular expressions","description":"path-to-regexp turns path strings into a regular expressions. In certain cases, path-to-regexp will output a regular expression that can be exploited to cause poor performance. Because JavaScript is single threaded and regex matching runs on the main thread, poor performance will block the event loop and lead to a DoS. The bad regular expression is generated any time you have two parameters within a single segment, separated by something that is not a period (.). For users of 0.1, upgrade to 0.1.10. All other users should upgrade to 8.0.0.","status":"published","published":"2024-09-09T19:07:40.313Z","modified":"2026-10-28T02:30:51.374084857Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-1333"],"updated_at":"2026-11-02T15:44:42.790566Z"},{"id":"CVE-2026-4867","title":"path-to-regexp vulnerable to Regular Expression Denial of Service via multiple route parameters","description":"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\nPatches:\n\nUpgrade to path-to-regexp@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\nWorkarounds:\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.","status":"published","published":"2026-03-26T16:16:25.501Z","modified":"2026-10-28T02:30:52.349197254Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-1333"],"updated_at":"2026-11-02T15:45:06.701612Z"},{"id":"DEBIAN-CVE-2026-4867","description":"Impact:  A 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.  Patches:  Upgrade to path-to-regexp@0.1.13  Custom regex patterns in route definitions (e.g., /:a-:b([^-/]+)-:c([^-/]+)) are not affected because they override the default capture group.  Workarounds:  All 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([^-/]+).  If paths cannot be rewritten and versions cannot be upgraded, another alternative is to limit the URL length.","status":"published","published":"2026-03-26T17:16:42.983Z","modified":"2026-10-01T03:03:16.507105916Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:45:56.444225Z"},{"id":"GHSA-37ch-88jc-xwx2","title":"path-to-regexp vulnerable to Regular Expression Denial of Service via multiple route parameters","description":"### 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/)","status":"published","published":"2026-03-27T20:04:53Z","modified":"2026-09-10T03:50:36.768786245Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-1333"],"updated_at":"2026-11-02T15:46:35.406455Z"},{"id":"GHSA-9wv6-86v2-598j","title":"path-to-regexp outputs backtracking regular expressions","description":"### Impact\n\nA bad regular expression is generated any time you have two parameters within a single segment, separated by something that is not a period (`.`). For example, `/:a-:b`.\n\n### Patches\n\nFor users of 0.1, upgrade to `0.1.10`. All other users should upgrade to `8.0.0`.\n\nThese versions add backtrack protection when a custom regex pattern is not provided:\n\n- [0.1.10](https://github.com/pillarjs/path-to-regexp/releases/tag/v0.1.10)\n- [1.9.0](https://github.com/pillarjs/path-to-regexp/releases/tag/v1.9.0)\n- [3.3.0](https://github.com/pillarjs/path-to-regexp/releases/tag/v3.3.0)\n- [6.3.0](https://github.com/pillarjs/path-to-regexp/releases/tag/v6.3.0)\n\nThey do not protect against vulnerable user supplied capture groups. Protecting against explicit user patterns is out of scope for old versions and not considered a vulnerability.\n\nVersion [7.1.0](https://github.com/pillarjs/path-to-regexp/releases/tag/v7.1.0) can enable `strict: true` and get an error when the regular expression might be bad.\n\nVersion [8.0.0](https://github.com/pillarjs/path-to-regexp/releases/tag/v8.0.0) removes the features that can cause a ReDoS.\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` to `/:a-:b([^-/]+)`.\n\nIf paths cannot be rewritten and versions cannot be upgraded, another alternative is to limit the URL length. For example, halving the attack string improves performance by 4x faster.\n\n### Details\n\nUsing `/:a-:b` will produce the regular expression `/^\\/([^\\/]+?)-([^\\/]+?)\\/?$/`. This can be exploited by a path such as `/a${'-a'.repeat(8_000)}/a`. [OWASP](https://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS) has a good example of why this occurs, but the TL;DR is the `/a` at the end ensures this route would never match but due to naive backtracking it will still attempt every combination of the `:a-:b` on the repeated 8,000 `-a`.\n\nBecause JavaScript is single threaded and regex matching runs on the main thread, poor performance will block the event loop and can lead to a DoS. In local benchmarks, exploiting the unsafe regex will result in performance that is over 1000x worse than the safe regex. In a more realistic environment using Express v4 and 10 concurrent connections, this translated to average latency of ~600ms vs 1ms.\n\n### References\n\n* [OWASP](https://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS)\n* [Detailed blog post](https://blakeembrey.com/posts/2024-09-web-redos/)","status":"published","published":"2024-09-09T20:19:15Z","modified":"2026-09-10T03:50:18.832560863Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"},{"version":"4.0","score":7.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P","level":"high"}],"cwes":["CWE-1333"],"updated_at":"2026-11-02T15:46:44.225359Z"},{"id":"ROOT-APP-NPM-CVE-2026-4867","title":"CVE-2026-4867 in @rootio/path-to-regexp - Patched by Root","description":"Root has patched CVE-2026-4867 in the @rootio/path-to-regexp package for Root:npm. Multiple fixed versions available.","status":"published","published":"2026-07-14T11:09:03Z","modified":"2026-07-14T15:09:21.013714022Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:53:27.649662Z"},{"id":"UBUNTU-CVE-2026-4867","description":"Impact: A 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. Patches: Upgrade to path-to-regexp@0.1.13 Custom regex patterns in route definitions (e.g., /:a-:b([^-/]+)-:c([^-/]+)) are not affected because they override the default capture group. Workarounds: All 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([^-/]+). If paths cannot be rewritten and versions cannot be upgraded, another alternative is to limit the URL length.","status":"withdrawn","published":"2026-03-26T17:16:00Z","modified":"2026-05-21T12:15:26.723751707Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T16:56:33.391918Z"},{"id":"CLSA-2026-1777250311","title":"TuxCare security update for path-to-regexp (1 CVE)","description":"TuxCare rebuilt path-to-regexp to address 1 CVE. Fixed in 0.1.3-tuxcare.2.","status":"published","published":"2026-08-04T14:52:28Z","modified":"2026-10-15T09:45:47.668441757Z","updated_at":"2026-11-02T15:43:44.384419Z"},{"id":"CLSA-2026-1779238048","title":"TuxCare security update for path-to-regexp (1 CVE)","description":"TuxCare rebuilt path-to-regexp to address 1 CVE. Fixed in 0.1.12-tuxcare.1.","status":"published","published":"2026-08-04T14:52:32Z","modified":"2026-10-15T09:48:03.302150656Z","updated_at":"2026-11-02T15:43:45.090939Z"},{"id":"CLSA-2026-1792663862","title":"TuxCare security update for path-to-regexp (1 CVE)","description":"TuxCare rebuilt path-to-regexp to address 1 CVE. Fixed in 0.1.7-tuxcare.2.","status":"published","published":"2026-10-22T10:11:02Z","modified":"2026-10-22T14:15:06.832946799Z","updated_at":"2026-11-02T15:43:54.672859Z"},{"id":"CLSA-2026-1792789806","title":"TuxCare security update for path-to-regexp (1 CVE)","description":"TuxCare rebuilt path-to-regexp to address 1 CVE. Fixed in 0.1.10-tuxcare.3.","status":"published","published":"2026-10-23T21:10:06Z","modified":"2026-10-24T01:30:03.00968466Z","updated_at":"2026-11-02T15:43:54.981307Z"}]}}