5.3

CVE-2018-21259: mattermost mattermost_server Improper Input Validation

CVSS: 5.3v3.1MediumModified
Published 19-06-2020Last modified 05-08-2024

Vulnerability summary

CVE-2018-21259 is a medium (CVSS 5.3) Improper Input Validation vulnerability in mattermost mattermost_server. EPSS estimates a 1.10% chance of exploitation in the next 30 days, higher than 65% of scored vulnerabilities.

Overall risk
21/100
0100
Low · default modelHow is this calculated?
CVSS score
5.3/10
010
Medium · v3.1 (NVD)
EPSS score
1.10%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

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 4.10.1, 4.9.4, and 4.8.2. It allows attackers to cause a denial of service (application hang) via a malformed link in a channel.

CVSS metrics

2 scores · 1 source · 2 versions

EPSS trend

Probability

1.10%

Chance of exploitation in the next 30 days

Percentile

65%

Versus all other CVEs

30-day change

0.00 pp

From 1.10% on 19-09-2026

19-09-202619-10-2026
EPSS score
1.10%

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

Mattermost1 product

1 vendor · 1 product

References

1 links