Use After Free Affecting ruby3.4-rails-8.1 package, versions <8.1.3.1-r1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-CHAINGUARDLATEST-RUBY34RAILS81-18598365
- published9 Aug 2026
- disclosed7 Aug 2026
Introduced: 7 Aug 2026
NewCVE-2026-71847 (opens in a new tab)How to fix?
Upgrade Chainguard ruby3.4-rails-8.1 to version 8.1.3.1-r1 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream ruby3.4-rails-8.1 package and not the ruby3.4-rails-8.1 package as distributed by Chainguard.
See How to fix? for Chainguard relevant fixed versions and status.
Ruby JSON is a JSON implementation for Ruby. From 2.20.0 until 2.21.2, Ruby's JSON native C extension clears the consumed JSON::ResumableParser input buffer but leaves state.start, state.cursor, and state.end pointing into released storage. When partial_value reconstructs an incomplete object containing duplicate keys, the duplicate-key warning path calls cursor_position, which dereferences those stale pointers. This results in a heap-use-after-free and can terminate the Ruby process. An attacker who can supply JSON stream data to an application using JSON::ResumableParser may cause process termination when the application calls partial_value on incomplete attacker-controlled input containing duplicate object keys. This issue has been fixed in version 2.21.2.