CVE-2026-90668: Unrealircd

High severity, CVSS 7.5. EPSS: 0.6% chance of exploitation in the next 30 days.

The webserver in UnrealIRCd 6.0.5 through 6.2.6 before 6.2.7 does not limit the number of HTTP request headers, which allows remote attackers to cause a denial of service (memory consumption and unresponsive server) via an HTTP request with an unlimited number of headers, if a websocket or JSON-RPC listener is enabled (disabled by default).

Affected products

• Unrealircd Unrealircd: from 6.0.5, before 6.2.7 (fixed in 6.2.7)

Published 2026-09-13. Last modified 2026-09-22.