What is CVE-2018-6535?

CVE-2018-6535 is a high-severity vulnerability in Icinga. CVSS score: 8.1/10. Published 2018-02-27.

How severe is CVE-2018-6535?

High severity. CVSS v3 base score is 8.1 out of 10.

Vulnerability in Icinga

CVE-2018-6535

An issue was discovered in Icinga 2.x through 2.8.1. The lack of a constant-time password comparison function can disclose the password to an attacker.

Published 2018-02-27 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.013 (69.9th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 70th percentile — 69.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.013 · newest: 0.013 · change: 0.000

Affected products

Icinga

References

github.com/Icinga/icinga2/pull/5715 (Third Party Advisory)
github.com/Icinga/icinga2/issues/4920 (Third Party Advisory)

Frequently asked questions

What is CVE-2018-6535?: CVE-2018-6535 is a high-severity vulnerability in Icinga. CVSS score: 8.1/10. Published 2018-02-27.
How severe is CVE-2018-6535?: High severity. CVSS v3 base score is 8.1 out of 10.