CVE-2026-90668 Details
Description
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).
A denial-of-service vulnerability has been identified in the webserver component of UnrealIRCd versions 6.0.5 through 6.2.6, prior to 6.2.7. The issue arises because the server does not limit the number of HTTP request headers, allowing remote attackers to consume excessive memory and cause the server to become unresponsive. This vulnerability is triggered by sending an HTTP request with an unlimited number of headers, but only if a websocket or JSON-RPC listener is enabled, which is off by default.
UnrealIRCd 6.2.7 has been released to address this vulnerability. Users can upgrade to this version or apply a hot-patch if they are using UnrealIRCd 6.1.x.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Sep 13, 2026CISA-ADP
Assessed Sep 14, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://forums.unrealircd.org/viewtopic.php?t=9483 | [email protected] | Content WallVendor |
| https://www.unrealircd.org/ | [email protected] | Vendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-770 | Allocation of Resources Without Limits or Throttling | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| UnrealIRCd | >= 6.0.5, <= 6.2.6 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 14, 2026 | CVE Modified | CISA-ADP |
| Sep 13, 2026 | New CVE Received | [email protected] |