CVE-2026-3234

Mod_proxy_cluster: mod_proxy_cluster: response body corruption via crlf injection

Published Mar 12, 2026 CVSS 3.1 · 4.3 Medium EPSS < 1% KEV · Not listed
Description
A flaw was found in mod_proxy_cluster. This vulnerability, a Carriage Return Line Feed (CRLF) injection in the decodeenc() function, allows a remote attacker to bypass input validation. By injecting CRLF sequences into the cluster configuration, an attacker can corrupt the response body of INFO endpoint responses. Exploitation requires network access to the MCMP protocol port, but no authentication is needed.

Remediation

Vendor Workaround

Restrict network access to the MCMP protocol port (typically 6666) for systems running Apache mod_proxy_cluster. Configure firewall rules to limit inbound connections to this port only from trusted internal or management networks. This action reduces the attack surface by preventing unauthorized remote access to the vulnerable service. A service reload or restart may be required for firewall changes to take full effect.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
CPEs cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:9
cpe:/a:redhat:enterprise_linux:10
cpe:/a:redhat:enterprise_linux:9
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description No description is available for this CVE. A flaw was found in mod_proxy_cluster. This vulnerability, a Carriage Return Line Feed (CRLF) injection in the decodeenc() function, allows a remote attacker to bypass input validation. By injecting CRLF sequences into the cluster configuration, an attacker can corrupt the response body of INFO endpoint responses. Exploitation requires network access to the MCMP protocol port, but no authentication is needed.
Title mod_proxy_cluster: apache mod_proxy_cluster: Response body corruption via CRLF injection Mod_proxy_cluster: mod_proxy_cluster: response body corruption via crlf injection
First Time appeared Redhat
Redhat enterprise Linux
Redhat jboss Core Services
CPEs cpe:/a:redhat:jboss_core_services:1
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
Redhat jboss Core Services
References
Type Values Removed Values Added
First Time appeared Apache
Apache mod Proxy Cluster
Vendors & Products Apache
Apache mod Proxy Cluster
Type Values Removed Values Added
Description No description is available for this CVE.
Title mod_proxy_cluster: apache mod_proxy_cluster: Response body corruption via CRLF injection
Weaknesses CWE-93
References
Metrics threat_severity

None

cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N'}

threat_severity

Low

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Nov 6, 2026, 6:24 PM
Reserved
Feb 26, 2026, 12:17 AM
Status
Awaiting Analysis
Published
Mar 12, 2026, 11:15 AM
Modified
Nov 6, 2026, 7:17 PM
Severity
Low
Public date
Feb 26, 2026, 12:00 AM