CVE-2026-4867
- Source
- https://cve.org/CVERecord?id=CVE-2026-4867
- Import Source
- https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-4867.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/CVE-2026-4867
- Aliases
- Downstream
- Related
- Published
- 2026-03-26T16:16:25.501Z
- Modified
- 2026-06-18T03:56:49.224863074Z
- Severity
-
- 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
- Summary
- path-to-regexp vulnerable to Regular Expression Denial of Service via multiple route parameters
- Details
-
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.
- Database specific
{ "cwe_ids": [ "CWE-1333" ], "cna_assigner": "openjs", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/4xxx/CVE-2026-4867.json", "unresolved_ranges": [ { "extracted_events": [ { "fixed": "0.1.13" } ], "source": "AFFECTED_FIELD" } ] }- References
Affected packages
Git / github.com/pillarjs/path-to-regexp
Affected ranges
- Type
- GIT
- Repo
- https://github.com/pillarjs/path-to-regexp
- Events
-
Introduced0 Unknown introduced commit / All previous commits are affectedFixed
- Database specific
{ "extracted_events": [ { "introduced": "0" }, { "fixed": "0.1.13" } ], "source": "CPE_RANGE", "cpe": "cpe:2.3:a:pillarjs:path-to-regexp:*:*:*:*:*:node.js:*:*" }