7.5

CVE-2025-20621: mattermost

CVSS: 7.5v3.1HighAnalyzed
AliasesGHSA-w6xh-c82w-h997GO-2025-3407CGA-46jr-3xr3-xc4w
Published 16-01-2025Last modified 16-01-2025
Open JSON

Vulnerability summary

CVE-2025-20621 is a high (CVSS 7.5) vulnerability in mattermost. EPSS estimates a 0.46% chance of exploitation in the next 30 days, higher than 38.4% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · 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 5
OPENSUSE-SU-2025:14704-1SUSE-SU-2025:0297-1CGA-C98V-56MV-HWH5CGA-PWC7-2PG9-FXHCCGA-X8GW-3WRC-9HM4

Timeline

  1. 16-01-2025
    PublishedVulnerability first disclosed.
  2. 16-01-2025
    Last modifiedVulnerability information updated.

Description

Mattermost versions 10.2.x <= 10.2.0, 9.11.x <= 9.11.5, 10.0.x <= 10.0.3, 10.1.x <= 10.1.3 fail to properly handle posts with attachments containing fields that cannot be cast to a String, which allows an attacker to cause the webapp to crash via creating and sending such a post to a channel.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.46%

Chance of exploitation in the next 30 days

Percentile

38%

Versus all other CVEs

30-day change

0.00 pp

From 0.46% on 20-09-2026

20-09-202620-10-2026
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

Chainguard2 products
  • mattermost-fips-10.5All versions (No fix recorded)
  • mattermost-fips-10.5-compatAll versions (No fix recorded)
Github.com/mattermost/mattermost-server2 products
  • v5All versions (No fix recorded)
  • v6All versions (No fix recorded)
Mattermost2 products
  • mattermost10.2.0 | ≥ 9.11.0, ≤ 9.11.5 | ≥ 10.0.0, ≤ 10.0.3 | ≥ 10.1.0, ≤ 10.1.3
  • mattermost_serverEOL≥ 9.11.0, < 9.11.6 | ≥ 10.0.0, < 10.0.4 | ≥ 10.1.0, < 10.1.4 | 10.2.0
Github.com/mattermost1 product
  • mattermost-server≥ 10.2.0+incompatible, < 10.2.1+incompatible
Github.com/mattermost/mattermost/server1 product
  • v8≥ 10.2.0, < 10.2.1 | ≥ 10.1.0, < 10.1.4 | ≥ 10.0.0, < 10.0.4 | ≥ 9.11.0, < 9.11.6 | < 8.0.0-20241127161322-25ff7a3779a5

5 vendors · 8 products

References

5 links