What is CVE-2017-18914?

CVE-2017-18914 is a medium-severity vulnerability in Mattermost Server, classified under Improper Check for Unusual or Exceptional Conditions. CVSS score: 5.3/10. Published 2020-06-19.

How severe is CVE-2017-18914?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in Mattermost Server

CVE-2017-18914

An issue was discovered in Mattermost Server before 3.8.2, 3.7.5, and 3.6.7. An external link can occur on an error page even if it is not on an allowlist.

Published 2020-06-19 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.008 (55.3th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 55.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Mattermost Server

Weakness classification (CWE)

CWE-754 — Improper Check for Unusual or Exceptional Conditions

References

mattermost.com/security-updates/ (Vendor Advisory)

Frequently asked questions

What is CVE-2017-18914?: CVE-2017-18914 is a medium-severity vulnerability in Mattermost Server, classified under Improper Check for Unusual or Exceptional Conditions. CVSS score: 5.3/10. Published 2020-06-19.
How severe is CVE-2017-18914?: Medium severity. CVSS v3 base score is 5.3 out of 10.