How severe is CVE-2019-12490?

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

Vulnerability in Simplemachines Simple Machines Forum

CVE-2019-12490

An issue was discovered in Simple Machines Forum (SMF) before 2.0.16. Reverse tabnabbing can occur because of use of _blank for external links.

Published 2020-01-22 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.013 (69.7th percentile), scored 2026-10-10.

Low probability of exploitation in the next 30 days, but still tracked. 70th percentile — 69.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.016 · newest: 0.013 · change: -0.003

Affected products

Simplemachines Simple Machines Forum

References

www.simplemachines.org/community/index.php (Issue Tracking, Vendor Advisory)
www.youtube.com/watch (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2019-12490?: CVE-2019-12490 is a medium-severity vulnerability in Simplemachines Simple Machines Forum. CVSS score: 6.5/10. Published 2020-01-22.
How severe is CVE-2019-12490?: Medium severity. CVSS v3 base score is 6.5 out of 10.