CVE-2026-4923
path-to-regexp vulnerable to Regular Expression Denial of Service via multiple wildcards
Vexday Risk Score
13Low
SSVC decision (CISA)
Track
No exploitation signal → monitor
CVSS 5.9EPSS 0.4%KEV nãoPoC —Nuclei —Metasploit —Patch —
Lifecycle
26 Mar 2026Published on NVD
Recommendation: Monitor — no exploitation signal at the moment.
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.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
path-to-regexp · path-to-regexpWant to know if your infrastructure is exposed to this?
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