CVE-2026-44186Network attack vector

Remote service interruption via FTP greeting loop

Published Jun 8, 2026 · Updated Jun 8, 2026

An infinite loop in mod_proxy_ftp in Apache HTTP Server 2.4.0 through 2.4.67 allows remote attackers to hang workers via a malicious FTP backend. The proxy_ftp_handler routine repeatedly scans an FTP 120 service-delay greeting without reaching its exit condition. The flaw requires FTP proxying to an attacker-controlled backend; occupied workers can exhaust the worker pool and interrupt service.

CVSS severity7.3
High
EPSS probability0.58%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An infinite loop in mod_proxy_ftp in Apache HTTP Server 2.4.0 through 2.4.67 allows remote attackers to hang workers via a malicious FTP backend. The proxy_ftp_handler routine repeatedly scans an FTP 120 service-delay greeting without reaching its exit condition. The flaw requires FTP proxying to an attacker-controlled backend; occupied workers can exhaust the worker pool and interrupt service.

The record

CVE
CVE-2026-44186
Published
Jun 8, 2026
Updated
Jun 8, 2026
Vendor
The Apache Software Foundation
Product
Apache HTTP Server
Classifications
CWE-835, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 8, 2026Record 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=2.4.0 <=2.4.67

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache HTTP Serverversion=2.4.0 <=2.4.67

Published CVSS scores

7.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

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-835Loop with Unreachable Exit Condition ('Infinite Loop')
T1499.004Application or System Exploitation

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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