Impact
Active Support number helpers accept strings containing scientific notation (e.g. 1e10000), which when converted to a string could be expanded into extremely large decimal representations. This can cause excessive memory allocation and CPU consumption when the expanded number is formatted, possibly resulting in a DoS vulnerability.
Releases
The fixed releases are available at the normal locations.
- CVE-2026-33176
- GHSA-2j26-frm8-cmj9
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/19dbab51ca086a657bb86458042bc44314916bcb.patch
- 8.0 - https://github.com/rails/rails/commit/ee2c59e730e5b8faed502cd2c573109df093f856.patch
- 7.2 - https://github.com/rails/rails/commit/ebd6be18120d1136511eb516338e27af25ac0a1a.patch
Credit
This issue was responsibly reported by hackerone researcher https://hackerone.com/manun