Inefficient Regular Expression Complexity in moment

Summary

moment is a JavaScript date library for parsing, validating, manipulating, and formatting dates. Affected versions of moment were found to use an inefficient parsing algorithm. Specifically using string-to-date parsing in moment (more specifically rfc2822 parsing, which is tried by default) has quadratic (N^2) complexity on specific inputs. Users may notice a noticeable slowdown is observed with inputs above 10k characters. Users who pass user-provided strings without sanity length checks to moment constructor are vulnerable to (Re)DoS attacks. The problem is patched in 2.29.4, the patch can be applied to all affected versions with minimal tweaking. Users are advised to upgrade. Users unable to upgrade should consider limiting date lengths accepted from user input.

Timeline

1. Jul 6, 2022, 12:00 AM UTCCVE published
2. Apr 22, 2025, 3:40 PM UTCCISA SSVC assessment

   Exploitation: poc · Automatable: yes · Technical impact: partial

3. Nov 3, 2025, 9:46 PM UTCRecord last updated

Affected versions

• moment moment

  From 2.18.0 · fixed in 2.29.4

• momentnpm

  From 2.18.0 · fixed in 2.29.4

• Moment.jsNuGet

  From 2.18.0 · fixed in 2.29.4

References 10