CVE-2026-33169 — Rails Active Support has a possible ReDoS vulnerability in number_to_delimited
Active Support is a toolkit of support libraries and Ruby core extensions extracted from the Rails framework. `NumberToDelimitedConverter` uses a lookahead-based regular express…
Published: 2026-03-23 · CVSS: 6.9 · CVSS 4.0
Active Support is a toolkit of support libraries and Ruby core extensions extracted from the Rails framework. `NumberToDelimitedConverter` uses a lookahead-based regular expression with `gsub!` to insert thousands delimiters. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, the interaction between the repeated lookahead group and `gsub!` can produce quadratic time complexity on long digit strings. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7