CVE-2022-23634

CVE-2022-23634 is a high-severity vulnerability in Puma with a CVSS 3.x base score of 8.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-404.

Key facts

Description

Puma is a Ruby/Rack web server built for parallelism. 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. The combination of these two behaviors (Puma not closing the body + Rails' Executor implementation) causes information leakage. 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. Upgrading to a patched Rails _or_ Puma version fixes the vulnerability.

Frequently asked questions

What is CVE-2022-23634?
Puma is a Ruby/Rack web server built for parallelism. 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. The combination of these two behaviors (Puma not closing the body + Rails' Executor implementation) causes information leakage. 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. Upgrading to a patched Rails _or_ Puma version fixes the vulnerability.
How severe is CVE-2022-23634?
CVE-2022-23634 has a CVSS 3.x base score of 8.0, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2022-23634 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2022-23634?
CVE-2022-23634 primarily affects Puma. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2022-23634?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2022-23634 published?
CVE-2022-23634 was published on 2022-02-11 and last updated on 2026-06-17.

References

Affected products (8)

More vulnerabilities in Puma

All CVEs affecting Puma →

Other CWE-404 vulnerabilities

Browse all CWE-404 vulnerabilities →