8.7

CVE-2026-90668: unrealircd

Deferred
Published 13-09-2026Last modified 14-09-2026

Vulnerability summary

CVE-2026-90668 is a high (CVSS 8.7) vulnerability in unrealircd. EPSS estimates a 0.58% chance of exploitation in the next 30 days, higher than 48.3% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 8.7 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 13-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
8.7/10
010
High · v4.0 (CVE.org)
EPSS score
0.58%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 13-09-2026
    PublishedVulnerability first disclosed.
  2. 14-09-2026
    Last modifiedVulnerability information updated.

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).

CVSS metrics

4 scores · 2 sources · 2 versions

EPSS trend

Probability

0.58%

Chance of exploitation in the next 30 days

Percentile

48%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.58% on 14-10-2026

14-10-202613-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Unrealircd1 product

1 vendor · 1 product

References

2 links