6.5

CVE-2025-21088: mattermost Incorrect Type Conversion or Cast

CVSS: 6.5v3.1MediumAnalyzed
AliasesGHSA-8j3q-gc9x-7972GO-2025-3393CGA-5qm4-g5m2-89rh
Published 15-01-2025Last modified 15-01-2025
Open JSON

Vulnerability summary

CVE-2025-21088 is a medium (CVSS 6.5) Incorrect Type Conversion or Cast vulnerability in mattermost. EPSS estimates a 0.56% chance of exploitation in the next 30 days, higher than 45.5% of scored vulnerabilities.

Overall risk
26/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.56%
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 7
OPENSUSE-SU-2025:14704-1SUSE-SU-2025:0297-1CGA-376V-X6MM-4383CGA-CGF5-4PP2-39XXCGA-CPXJ-8GVF-CWG6CGA-CVHH-G5CJ-97M6

Timeline

  1. 15-01-2025
    PublishedVulnerability first disclosed.
  2. 15-01-2025
    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 validate the style of proto supplied to an action's style in post.props.attachments, which allows an attacker to crash the frontend via crafted malicious input.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.56%

Chance of exploitation in the next 30 days

Percentile

46%

Versus all other CVEs

30-day change

0.00 pp

From 0.56% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.56%

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

6 links