GHSA-rmj8-8hhh-gv5h
HIGHPuma used with Rails may lead to Information Exposure
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
puma💎pumaReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.
Description
Impact
Prior to puma version 5.6.2, puma may not always call close on the response body. Rails, prior to version 7.0.2.2, depended on the response body being closed in order for its CurrentAttributes implementation to work correctly.
From Rails:
Under certain circumstances response bodies will not be closed, for example a bug in a webserver[1] or a bug in a Rack middleware. In the event a response is not notified of a close, ActionDispatch::Executor will not know to reset thread local state for the next request. This can lead to data being leaked to subsequent requests, especially when interacting with ActiveSupport::CurrentAttributes.
The combination of these two behaviors (Puma not closing the body + Rails' Executor implementation) causes information leakage.
Patches
This problem is fixed in Puma versions 5.6.2 and 4.3.11.
This problem is fixed in Rails versions 7.02.2, 6.1.4.6, 6.0.4.6, and 5.2.6.2.
See: https://github.com/advisories/GHSA-wh98-p28r-vrc9 for details about the rails vulnerability
Upgrading to a patched Rails or Puma version fixes the vulnerability.
Workarounds
Upgrade to Rails versions 7.02.2, 6.1.4.6, 6.0.4.6, and 5.2.6.2.
The Rails CVE includes a middleware that can be used instead.
References
- Rails CVE: CVE-2022-23633
For more information
If you have any questions or comments about this advisory:
- Open an issue in puma
- See our security policy
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | puma | ≥ 5.0.0&&< 5.6.2 | 5.6.2 |
| 💎RubyGems | puma | all versions | 4.3.11 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for puma. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update puma to 5.6.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-rmj8-8hhh-gv5h is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-rmj8-8hhh-gv5h is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-rmj8-8hhh-gv5h. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-rmj8-8hhh-gv5h in your dependencies?
O3 detects GHSA-rmj8-8hhh-gv5h across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.