4.9

CVE-2017-18918: mattermost mattermost_server Improper Certificate Validation

CVSS: 4.9v3.1MediumModified
AliasesGHSA-5ghq-28r7-qwfjGO-2026-4460
Published 19-06-2020Last modified 05-08-2024
Open JSON

Vulnerability summary

CVE-2017-18918 is a medium (CVSS 4.9) Improper Certificate Validation vulnerability in mattermost mattermost_server. EPSS estimates a 0.46% chance of exploitation in the next 30 days, higher than 38.7% of scored vulnerabilities.

Overall risk
20/100
0100
Low · default modelHow is this calculated?
CVSS score
4.9/10
010
Medium · v3.1 (NVD)
EPSS score
0.46%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 2 · Related 2
OPENSUSE-SU-2026:21483-1SUSE-SU-2026:0757-1

Timeline

  1. 19-06-2020
    PublishedVulnerability first disclosed.
  2. 05-08-2024
    Last modifiedVulnerability information updated.

Description

An issue was discovered in Mattermost Server before 3.7.3 and 3.6.5. A System Administrator can place a SAML certificate at an arbitrary pathname.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

0.46%

Chance of exploitation in the next 30 days

Percentile

39%

Versus all other CVEs

30-day change

0.00 pp

From 0.46% on 22-09-2026

22-09-202622-10-2026
EPSS score
0.46%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Github.com/mattermost1 product
  • mattermost-server< 3.6.5 | ≥ 3.7.0, < 3.7.3 | ≥ 3.7.0+incompatible, < 3.7.3+incompatible
Mattermost1 product

2 vendors · 2 products

References

7 links