6.5

CVE-2026-9602: mattermost Uncontrolled Resource Consumption

CVSS: 6.5v3.1MediumAnalyzed
Published 17-07-2026Last modified 17-07-2026
Open JSON

Vulnerability summary

CVE-2026-9602 is a medium (CVSS 6.5) Uncontrolled Resource Consumption vulnerability in mattermost. EPSS estimates a 0.42% chance of exploitation in the next 30 days, higher than 35.1% of scored vulnerabilities.

Overall risk
26/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.42%
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. 17-07-2026
    PublishedVulnerability first disclosed.
  2. 17-07-2026
    Last modifiedVulnerability information updated.

Description

Mattermost Desktop App versions <=6.2 6.0.2 5.6.13.0 fail to validate payloads sent from the Mattermost Web App to the Desktop App which allows a malicious server owner to crash the Mattermost Desktop App via changing the payload of a method to a malformed one. Mattermost Advisory ID: MMSA-2026-00678

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.42%

Chance of exploitation in the next 30 days

Percentile

35%

Versus all other CVEs

30-day change

0.00 pp

From 0.42% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.42%

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

Mattermost2 products
  • mattermost≤ 6.0.2 | ≤ 5.6.13
  • mattermost_desktop≥ 5.6.13, < 5.13.7 | ≥ 6.0.2, < 6.2.1 | > 6.2.1, < 6.3 | < 5.13.7 | ≥ 6.0.0, ≤ 6.0.2 | ≥ 6.2.0, < 6.2.1

1 vendor · 2 products

References

1 links