CVE-2022-26377Public exploitNetwork attack vector

Request smuggling via conflicting body framing

Published Jun 8, 2022 · Updated Aug 3, 2024

HTTP request smuggling in Apache HTTP Server 2.4.53 and earlier allows remote attackers to inject requests through mod_proxy_ajp. The handler accepts only an exact chunked Transfer-Encoding value but otherwise falls back to Content-Length, allowing conflicting framing to desynchronize HTTP and AJP parsing. The server must load mod_proxy and mod_proxy_ajp and route an exposed path to an AJP backend, where smuggled requests can bypass intended front-end request handling.

CVSS severity7.5
High
EPSS probability21.08%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

HTTP request smuggling in Apache HTTP Server 2.4.53 and earlier allows remote attackers to inject requests through mod_proxy_ajp. The handler accepts only an exact chunked Transfer-Encoding value but otherwise falls back to Content-Length, allowing conflicting framing to desynchronize HTTP and AJP parsing. The server must load mod_proxy and mod_proxy_ajp and route an exposed path to an AJP backend, where smuggled requests can bypass intended front-end request handling.

The record

CVE
CVE-2022-26377
Published
Jun 8, 2022
Updated
Aug 3, 2024
Vendor
The Apache Software Foundation
Product
Apache HTTP Server
Classifications
CWE-444, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 8, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record 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=Apache HTTP Server 2.4 <=2.4.53

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache HTTP Serverversion=Apache HTTP Server 2.4 <=2.4.53

Published CVSS scores

6.5Amazon LinuxCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:L
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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.

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No observations available

Sep 11, 2026Sep 17, 2026
Latest reporting daySep 17, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
T1190Exploit Public-Facing Application

Public exploit references

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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