CVE-2026-4923
Description
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 tool such as https://makenowjust-labs.github.io/recheck/playground/ to confirm whether a path is vulnerable.
How to fix
- pillarjs path-to-regexp8.4.0 or later
- path-to-regexp8.4.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| pillarjs path-to-regexp | 8.0.0 ≤ v < 8.4.0 | 8.4.0 |
| path-to-regexpnpm | 8.0.0 ≤ v < 8.4.0 | 8.4.0 |
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Attack Surface Management
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