Regular Expression Denial of Service in debug

Affected versions of `debug` are vulnerable to regular expression denial of service when untrusted user input is passed into the `o` formatter. As it takes 50,000 characters to block the event loop for 2 seconds, this issue is a low severity issue. This was later re-introduced in version v3.2.0, and then repatched in versions 3.2.7 and 4.3.1. ## Recommendation Version 2.x.x: Update to version 2.6.9 or later. Version 3.1.x: Update to version 3.1.0 or later. Version 3.2.x: Update to version 3.2.7 or later. Version 4.x.x: Update to version 4.3.1 or later.

Source published

9 Aug 2018 20:18:07 UTC

Source modified

10 Sep 2026 03:47:07 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

Publisher rating · LOW