What is CVE-2018-1158?

CVE-2018-1158 is a medium-severity vulnerability in Mikrotik Routeros, classified under Uncontrolled Recursion. CVSS score: 6.5/10. Published 2018-08-23.

How severe is CVE-2018-1158?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Mikrotik Routeros

CVE-2018-1158

Mikrotik RouterOS before 6.42.7 and 6.40.9 is vulnerable to a stack exhaustion vulnerability. An authenticated remote attacker can crash the HTTP server via recursive parsing of JSON.

Published 2018-08-23 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.025 (84.0th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 84th percentile — 84.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.025 · newest: 0.025 · change: 0.000

Affected products

Mikrotik Routeros

Weakness classification (CWE)

CWE-674 — Uncontrolled Recursion

References

www.tenable.com/security/research/tra-2018-21 (Exploit, Third Party Advisory)
mikrotik.com/download/changelogs (Vendor Advisory)
mikrotik.com/download/changelogs/bugfix-release-tree (Vendor Advisory)
seclists.org/fulldisclosure/2019/Jul/20 (mailing-list)

Frequently asked questions

What is CVE-2018-1158?: CVE-2018-1158 is a medium-severity vulnerability in Mikrotik Routeros, classified under Uncontrolled Recursion. CVSS score: 6.5/10. Published 2018-08-23.
How severe is CVE-2018-1158?: Medium severity. CVSS v3 base score is 6.5 out of 10.