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UnrealIRCd labeled-response module allows command injection via label tag

Priority MEDIUM 52CWE-140Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

The labeled-response module in UnrealIRCd 6.0.0 before 6.2.7.1 does not escape the IRCv3 "label" message tag when it echoes the tag into replies. Any user on a network with two or more linked servers can inject server-to-server commands that run with server authority. The weakness is classified as CWE-140 (Improper Neutralization of Delimiters), and CVSS 3.1 scores it 8.6 HIGH. CISA has not added it to KEV.

Written with Claude Haiku 5.5 from the sources below · 2026-11-08

Description from the CNA

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.

Why it matters now

Fix Fixed UnrealIRCd (UnrealIRCd): 6.2.7.1

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
UnrealIRCdUnrealIRCdbefore 6.2.7.16.2.7.1Patch availableCNA
  • UnrealIRCd VendorUnrealIRCd Affected before 6.2.7.1 Fixed in 6.2.7.1 Patch available CNA

Remediation

Upgrade UnrealIRCd to 6.2.7.1 or later, which fixes the issue.

Written with Claude Haiku 5.5 from the sources below · 2026-11-08

  • Fix · CNA UnrealIRCd (UnrealIRCd) Fixed in 6.2.7.1

Timeline

  1. 2026-11-08 Threatist record created from CVE-2026-114713
  2. 2026-11-08 Alias added: GHSA-237f-p9h6-wq4r

References

  • TI-2010-01989 UnrealIRCd 3.2.8.1, as distributed on certain mirror sites from November 2009 through… CVSS 2.0HIGH 7.5
  • TI-2026-61634 Resource allocation without limits in UnrealIRCd CVSS 4.0HIGH 8.7
  • TI-2016-06143 The m_authenticate function in modules/m_sasl.c in UnrealIRCd before 3.2.10.7 and 4.x… CVSS 3.0HIGH 8.1
  • TI-2023-27714 A buffer overflow in websockets in UnrealIRCd 6.1.0 through 6.1.3 before 6.1.4 allows an… CVSS 3.1HIGH 7.5
  • TI-2009-04649 Buffer overflow in UnrealIRCd 3.2beta11 through 3.2.8, when allow::options::noident is… CVSS 2.0MEDIUM 6.8
  • TI-2013-06048 UnrealIRCd 3.2.10 before 3.2.10.2 allows remote attackers to cause a denial of service… CVSS 2.0MEDIUM 5.0
See all 8 →

Sources