The labeled-response module in UnrealIRCd 6.0.0 before 6.2.7.1 does not escape the IRCv3 "label" message tag when echoing it into replies, which allows any user on a network with two or more linked servers to inject server-to-server commands that are executed with server authority.

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Fixes

Solution

Upgrade to UnrealIRCd 6.2.7.1 or later. Alternatively, apply the hot-patch to fix the issue without restart: ./unrealircd hot-patch bundle-20261107


Workaround

Add the following line to the configuration file of all servers until the patch or upgrade is applied: blacklist-module "labeled-response";

History

Sun, 08 Nov 2026 03:45:00 +0000

Type Values Removed Values Added
Title UnrealIRCd label‑response module fails to escape IRCv3 label tag, enabling server‑to‑server command injection

Sun, 08 Nov 2026 02:45:00 +0000

Type Values Removed Values Added
Description The labeled-response module in UnrealIRCd 6.0.0 before 6.2.7.1 does not escape the IRCv3 "label" message tag when echoing it into replies, which allows any user on a network with two or more linked servers to inject server-to-server commands that are executed with server authority.
First Time appeared Unrealircd
Unrealircd unrealircd
Weaknesses CWE-140
CPEs cpe:2.3:a:unrealircd:unrealircd:*:*:*:*:*:*:*:*
Vendors & Products Unrealircd
Unrealircd unrealircd
References
Metrics cvssV3_1

{'score': 8.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-11-08T02:31:48.387Z

Reserved: 2026-10-22T00:56:41.381Z

Link: CVE-2026-114713

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2026-11-08T03:16:33.410

Modified: 2026-11-08T03:16:36.987

Link: CVE-2026-114713

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-11-08T04:30:14Z

Weaknesses