Is CVE-2026-33169 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-33169 being exploited in the wild.

How severe is CVE-2026-33169?

Medium severity, with a CVSS score of 4, published 23 March 2026.

Which products and versions are affected?

activesupport (RubyGems) ECOSYSTEM:introduced=8.1.0.beta1,fixed=8.1.2.1.

Is there a fix for CVE-2026-33169?

Yes. activesupport (RubyGems): upgrade to 8.1.2.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Am I affected by CVE-2026-33169?

Check whether you run activesupport (RubyGems) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-33169: Rails Active Support has a possible ReDoS vulnerability in number_to_delimited

CVE-2026-33169 · Severity: medium · CVSS 4 · Published 2026-03-23

### 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.

### Credit This issue was responsibly reported by Hackerone researcher [scyoon](https://hackerone.com/scyoon).

Technologies: activesupport (RubyGems). Vendors: RubyGems.

Quick answers

Is CVE-2026-33169 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-33169 being exploited in the wild.
How severe is CVE-2026-33169?: Medium severity, with a CVSS score of 4, published 23 March 2026.
Which products and versions are affected?: activesupport (RubyGems) ECOSYSTEM:introduced=8.1.0.beta1,fixed=8.1.2.1.
Is there a fix for CVE-2026-33169?: Yes. activesupport (RubyGems): upgrade to 8.1.2.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2026-33169?: Check whether you run activesupport (RubyGems) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

activesupport (RubyGems): upgrade to 8.1.2.1 or later
```
bundle update activesupport
```

Affected products

activesupport (RubyGems) ECOSYSTEM:introduced=8.1.0.beta1,fixed=8.1.2.1

Identifiers

CVE-2026-33169
GHSA-cg4j-q9v8-6v38

References

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