CVE-2026-114713 in plain words
Written by Varaxon from the sources below. Last checked .
- What an attacker can do
- UnrealIRCd does not escape the IRCv3 label tag when it echoes the tag back in replies. On a network with two or more linked servers, any ordinary user can use that to slip extra lines into server-to-server traffic and have commands run with server or IRC operator authority. The project says this lets a normal user disconnect or ban other users, among other things, and calls it the most critical issue found in UnrealIRCd in 15 years.
- Who is affected
- UnrealIRCd 6.0.0 up to and including 6.2.7, on networks with two or more linked servers. The project says UnrealIRCd 5, which reached end of life in 2023, is affected in the same way, and that other end-of-life versions have not been checked.
- What to do first
- First, as an IRC operator, add the spam filter rule given in the project's advisory. It protects every linked server at once, provided all servers run 6.0.4 or newer. Then either run the hot-patch bundle-20261107 on every server, which needs no restart, or upgrade to 6.2.7.1 and restart. Confirm that the labeled-response module reports the hot-patch bundle or 6.2.7.1. The same release fixes eight other security issues.
How to check if you are exposed to CVE-2026-114713
- Find every UnrealIRCd system you or your clients run, including ones exposed to the internet. Those come first: CISA only lists flaws attackers are already using.
- Compare each version with the fixed versions in the vendor advisory below. Where no fix exists yet, apply the vendor’s mitigation or take the system off the internet.
- Run a credentialed vulnerability scan to catch the systems you missed, then check that the next scan no longer reports CVE-2026-114713.
US federal agencies had to fix this by 2026-11-16. Everyone else should treat that deadline as a guide: if it has passed, this is overdue.
Timeline
- · Added to CISA's Known Exploited Vulnerabilities catalog
- · Fix-by date for US federal agencies, still ahead
Vendor advisories and fixes
Weakness type
Keep going
- Exploited this month
- All exploited CVEs
- Check another CVE
- What is CISA KEV?
- What is EPSS?
- CISA KEV report, October 2026
Sources: CISA Known Exploited Vulnerabilities catalog (version 2026.11.13); EPSS data from FIRST.org; CVSS and descriptions from the NIST National Vulnerability Database. Checked 2026-11-14. This product uses the NVD API but is not endorsed or certified by the NVD.