Impact
NumberToDelimitedConverter used a regular expression with gsub! to insert thousands delimiters. This could produce quadratic time complexity on long digit strings.
Releases
The fixed releases are available at the normal locations.
- CVE-2026-33169
- GHSA-cg4j-q9v8-6v38
Versions affected
- activesupport >= 8.1, < 8.1.2.1 (patched in 8.1.2.1)
- activesupport >= 8.0, < 8.0.4.1 (patched in 8.0.4.1)
- activesupport < 7.2.3.1 (patched in 7.2.3.1)
Patches
- 8.1 - https://github.com/rails/rails/commit/ec1a0e215efd27a3b3911aae6df978a80f456a49.patch
- 8.0 - https://github.com/rails/rails/commit/29154f1097da13d48fdb3200760b3e3da66dcb11.patch
- 7.2 - https://github.com/rails/rails/commit/b54a4b373c6f042cab6ee2033246b1c9ecc38974.patch
Credit
This issue was responsibly reported by Seokchan Yoon (https://ch4n3.kr).