CVE-2022-23634Network attack vector

Cross-request information disclosure via skipped response closure

Published Feb 11, 2022 · Updated Apr 23, 2025

Information disclosure in Puma before 4.3.11 and 5.0.0 through 5.6.1 allows remote attackers to read data from earlier Rails requests. In handle_request, cleanup exceptions can bypass res_body.close, preventing Rack::BodyProxy callbacks from resetting thread-local CurrentAttributes. Exploitation requires a Rails application that depends on response-body closure for request-state cleanup; the reported consequence is cross-request data exposure.

CVSS severity8.0
High
EPSS probability2.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Puma before 4.3.11 and 5.0.0 through 5.6.1 allows remote attackers to read data from earlier Rails requests. In handle_request, cleanup exceptions can bypass res_body.close, preventing Rack::BodyProxy callbacks from resetting thread-local CurrentAttributes. Exploitation requires a Rails application that depends on response-body closure for request-state cleanup; the reported consequence is cross-request data exposure.

The record

CVE
CVE-2022-23634
Published
Feb 11, 2022
Updated
Apr 23, 2025
Vendor
Puma
Product
Puma
Classifications
CWE-200, CWE-404, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 11, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 4.3.11
  2. Affected versionversion=>= 5.0.0, < 5.6.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Puma · Pumaversion=< 4.3.11; version=>= 5.0.0, < 5.6.2

Published CVSS scores

8.0GitHubCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N
5.9NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
4.3NIST NVDAV:N/AC:M/Au:N/C:P/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
CWE-404Improper Resource Shutdown or Release
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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