CVE•Published 2026-08-17•Modified 2026-08-19•0 articles on news•6 live references•NVD data

CVE-2026-9693Mattermost · Mattermost_server

Vulnerability data via NVD (ingested)

CVSS v3.1

3.5

LOW

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N

EPSS percentile

Exploit Prediction Scoring System · top 95% of all CVEs

Weaknesses (CWE)

CWE-459Incomplete Cleanup

Description

Mattermost versions 10.11.x <= 10.11.20, 11.7.x <= 11.7.5 Mattermost fails to remove thread membership records when a user is removed from or leaves a team, which allows a previously removed user who is later re-invited to the team to view private channel thread root post content and metadata via the team threads API.. Mattermost Advisory ID: MMSA-2026-00682

Timeline

Published 2026-08-17

Modified 2026-08-19

External references

NVD MITRE Exploit-DB Sploitus trickest/cve VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common). Live host counts are a Premium feature.

Shodan · vuln tag

vuln:CVE-2026-9693

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Mattermost Mattermost Server"

All exposed Mattermost Mattermost Server instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Mattermost Server"

HTTP body or banner mentions "Mattermost Server" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2026-9693