CVE-2026-33176: Rubyonrails Rails

High severity, CVSS 7.5. EPSS: 0.8% chance of exploitation in the next 30 days.

Active Support is a toolkit of support libraries and Ruby core extensions extracted from the Rails framework. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, Active Support number helpers accept strings containing scientific notation (e.g. `1e10000`), which `BigDecimal` expands 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. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.

Affected products

• Rubyonrails Rails: before 7.2.3.1 (fixed in 7.2.3.1); from 8.0.0, before 8.0.4.1 (fixed in 8.0.4.1); from 8.1.0, before 8.1.2.1 (fixed in 8.1.2.1)

Published 2026-03-24. Last modified 2026-06-17.