CVE-2026-33169
Description
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
Debian Mixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Affected | — |
| sid | Fixed | 2:7.2.3.1+dfsg-1 |
| forky | Fixed | 2:7.2.3.1+dfsg-1 |
| bullseye | Affected | — |
| bookworm | Affected | — |
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| RubyGems | activesupport | <~> 7.2.3, >= 7.2.3.1 | ~> 7.2.3, >= 7.2.3.1 |
| RubyGems | activesupport | >=8.1.0.beta1,<8.1.2.1 | 8.1.2.1 |
| RubyGems | activesupport | >=8.0.0.beta1,<8.0.4.1 | 8.0.4.1 |
| RubyGems | activesupport | <7.2.3.1 | 7.2.3.1 |
| RUBYGEMS | activesupport | < 7.2.3.1 | 7.2.3.1 |
| RUBYGEMS | activesupport | >= 8.0.0.beta1, < 8.0.4.1 | 8.0.4.1 |
| RUBYGEMS | activesupport | >= 8.1.0.beta1, < 8.1.2.1 | 8.1.2.1 |
Application impact
| Vendor | Product | Versions | Fixed |
|---|---|---|---|
| gcp | | |
References
- https://github.com/rails/rails/security/advisories/GHSA-cg4j-q9v8-6v38
- https://www.suse.com/security/cve/CVE-2026-33169.html
- https://nvd.nist.gov/vuln/detail/CVE-2026-33169
- https://github.com/rails/rails/commit/29154f1097da13d48fdb3200760b3e3da66dcb11
- https://github.com/rails/rails/commit/b54a4b373c6f042cab6ee2033246b1c9ecc38974
- https://github.com/rails/rails/commit/ec1a0e215efd27a3b3911aae6df978a80f456a49
- https://github.com/rails/rails
- https://github.com/rails/rails/releases/tag/v7.2.3.1
- https://github.com/rails/rails/releases/tag/v8.0.4.1
- https://github.com/rails/rails/releases/tag/v8.1.2.1
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/activesupport/CVE-2026-33169.yml
- https://security-tracker.debian.org/tracker/CVE-2026-33169
- https://github.com/advisories/GHSA-cg4j-q9v8-6v38
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.