8.8

CVE-2018-21263: mattermost mattermost_server Improper Authentication

CVSS: 8.8v3.1HighModified
Published 19-06-2020Last modified 05-08-2024
Open JSON

Vulnerability summary

CVE-2018-21263 is a high (CVSS 8.8) Improper Authentication vulnerability in mattermost mattermost_server. EPSS estimates a 0.93% chance of exploitation in the next 30 days, higher than 59.9% of scored vulnerabilities.

Overall risk
35/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.8/10
010
High · v3.1 (NVD)
EPSS score
0.93%
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 4.7.0, 4.6.2, and 4.5.2. An attacker could authenticate to a different user's account via a crafted SAML response.

CVSS metrics

2 scores · 1 source · 2 versions

EPSS trend

Probability

0.93%

Chance of exploitation in the next 30 days

Percentile

60%

Versus all other CVEs

30-day change

0.00 pp

From 0.93% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.93%

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
  • mattermost_server< 4.5.2 | ≥ 4.6.0, < 4.6.2 | 4.7.0:rc1 | 4.7.0:rc2 | 4.7.0:rc3 | 4.7.0:rc4

1 vendor · 1 product

References

1 links