What is CVE-2017-12156?

CVE-2017-12156 is a medium-severity vulnerability in Moodle, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2017-09-18.

How severe is CVE-2017-12156?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Moodle

CVE-2017-12156

Moodle 3.x has XSS in the contact form on the "non-respondents" page in non-anonymous feedback.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2017-09-18 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.012 (68.8th percentile), scored 2026-10-25.

Low probability of exploitation in the next 30 days, but still tracked. 69th percentile — 68.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.011 · newest: 0.012 · change: +0.002

Affected products

Moodle — versions 3.0.0, 3.0.1, 3.0.2
Moodle 3.x — versions Moodle 3.x

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

www.securityfocus.com/bid/100867 (VDB Entry, Third Party Advisory, vdb-entry)
moodle.org/mod/forum/discuss.php (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2017-12156?: CVE-2017-12156 is a medium-severity vulnerability in Moodle, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2017-09-18.
How severe is CVE-2017-12156?: Medium severity. CVSS v3 base score is 6.1 out of 10.