What is CVE-2018-5206?

CVE-2018-5206 is a critical-severity vulnerability in Irssi, classified under NULL Pointer Dereference. CVSS score: 9.8/10. Published 2018-01-06.

How severe is CVE-2018-5206?

Critical severity. CVSS v3 base score is 9.8 out of 10.

NULL pointer dereference in Irssi

CVE-2018-5206

When the channel topic is set without specifying a sender, Irssi before 1.0.6 may dereference a NULL pointer.

Published 2018-01-06 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.022 (81.5th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 81st percentile — 81.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.022 · newest: 0.022 · change: 0.000

Affected products

Irssi
Debian Linux — versions 9.0

Weakness classification (CWE)

CWE-476 — NULL Pointer Dereference

References

www.debian.org/security/2018/dsa-4162 (vendor-advisory, Third Party Advisory)
irssi.org/security/irssi_sa_2018_01.txt (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2018-5206?: CVE-2018-5206 is a critical-severity vulnerability in Irssi, classified under NULL Pointer Dereference. CVSS score: 9.8/10. Published 2018-01-06.
How severe is CVE-2018-5206?: Critical severity. CVSS v3 base score is 9.8 out of 10.