CVE-2022-24790Network attack vector

Request smuggling via lenient HTTP parsing

Published Mar 30, 2022 · Updated Apr 23, 2025

HTTP request smuggling in Puma before 4.3.12 and 5.0.0 through 5.6.3 allows remote attackers to smuggle requests through a proxy. Puma's request-body parser accepts unsupported or repeated Transfer-Encoding values, malformed Content-Length and chunk sizes, and invalid chunk endings instead of rejecting them. Exploitation requires a front-end proxy that parses the crafted request differently, allowing attacker-controlled bytes to become a subsequent request.

CVSS severity9.1
Critical
EPSS probability2.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

HTTP request smuggling in Puma before 4.3.12 and 5.0.0 through 5.6.3 allows remote attackers to smuggle requests through a proxy. Puma's request-body parser accepts unsupported or repeated Transfer-Encoding values, malformed Content-Length and chunk sizes, and invalid chunk endings instead of rejecting them. Exploitation requires a front-end proxy that parses the crafted request differently, allowing attacker-controlled bytes to become a subsequent request.

The record

CVE
CVE-2022-24790
Published
Mar 30, 2022
Updated
Apr 23, 2025
Vendor
Puma
Product
Puma
Classifications
CWE-444, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 30, 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=< 4.3.12
  2. Affected versionversion=>= 5.0.0, < 5.6.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Puma · Pumaversion=< 4.3.12; version=>= 5.0.0, < 5.6.4

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
9.1GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:P/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-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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