This page lists publicly disclosed CVE vulnerabilities affecting pillarjs path-to-regexp (linked via NVD CPE). Each row includes severity scores, summaries, and publication dates to help identify and analyze security issues.
| CVE | Summary | Source | Max CVSS | EPSS % | Published | Updated |
|---|---|---|---|---|---|---|
| CVE-2026-4926 | Impact: A bad regular expression is generated any time you have multiple sequential optional groups (curly brace syntax), such as `{a}{b}{c}:z`. The generated regex grows exponentially with the number of groups, causing denial of service. Patches: Fixed in version 8.4.0. Workarounds: Limit the number of sequential optional groups in route patterns. Avoid passing user-controlled input as route patterns. | ce714d77-add3-4f53-aff5-83d477b104bb | 7.5 | 0.79% | 2026-03-26 | 2026-07-17 |
| CVE-2026-4923 | Impact: When using multiple wildcards, combined with at least one parameter, a regular expression can be generated that is vulnerable to ReDoS. This backtracking vulnerability requires the second wildcard to be somewhere other than the end of the path. Unsafe examples: /*foo-*bar-:baz /*a-:b-*c-:d /x/*a-:b/*c/y Safe examples: /*foo-:bar /*foo-:bar-*baz Patches: Upgrade to version 8.4.0. Workarounds: If you are using multiple wildcard parameters, you can check the regex output with a too | ce714d77-add3-4f53-aff5-83d477b104bb | 5.9 | 0.35% | 2026-03-26 | 2026-06-17 |
| CVE-2026-4867 | 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 [email protected] 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 [email protected] | ce714d77-add3-4f53-aff5-83d477b104bb | 7.5 | 0.50% | 2026-03-26 | 2026-06-17 |