HOMEVULNERABILITIESCVE-2026-3636
MEDIUM

CVE-2026-3636

CWE-200Published: May 22, 2026· Updated: May 22, 2026

4.3
CVSS v3.1
EPSS:0.02%probability of exploitation in 30 daysPercentile:6.5th

Official Description

Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to sanitize team member data when returned via API to users without elevated permissions which allows a user without permissions to get data about team members roles via invoking various team API endpoints.. Mattermost Advisory ID: MMSA-2026-00626

NVD Source

Technical Analysis

CVE-2026-3636 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

From a weakness classification perspective (CWE-200): Information exposure vulnerabilities leak sensitive data to unauthorized actors.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.Low
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityLow
IntegrityNone
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Affected Vendors & Products

mattermost1 product
mattermost server
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
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Official Patches & Advisories

ADVISORYhttps://mattermost.com/security-updates

All References (1)

→
https://mattermost.com/security-updatesVendor Advisory

Quick Facts

CVE IDCVE-2026-3636
CVSS Score4.3 / 10
SeverityMEDIUM
WeaknessCWE-200
CISA KEVNo
EPSS (30d)0.02%
Affected1 vendor
PublishedMay 22, 2026

Related CVEs (CWE-200)

CVE-2026-27604
10.0
CVE-2026-40965
10.0
CVE-2026-54305
9.9
CVE-2026-21515
9.9
CVE-2026-40498
9.8
CVE-2026-43992
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2026-3636 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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