CVE-2026-3234
Mod_proxy_cluster: mod_proxy_cluster: response body corruption via crlf injection
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.
Fixes and workarounds
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.
Source: CNA: redhatAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| Red Hat Enterprise Linux 10 Red Hat mod_proxy_cluster
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 9 Red Hat mod_proxy_cluster
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat JBoss Core Services Red Hat jbcs-httpd24-mod_proxy_cluster
https://access.redhat.com/jbossnetwork/restricted/listSoftware.html |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat JBoss Core Services Red Hat mod_proxy_cluster
https://access.redhat.com/jbossnetwork/restricted/listSoftware.html |
Range not reported
Other versions: affected |
CNA: redhat |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 3.1 / 4.3 medium |
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N | CNA: redhat |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://access.redhat.com/security/cve/CVE-2026-3234CNA: redhat · vdb-entry, x_refsource_REDHAT
- https://bugzilla.redhat.com/show_bug.cgi?id=2442889CNA: redhat · issue-tracking, x_refsource_REDHAT