CVE-2026-20796

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Source
https://cve.org/CVERecord?id=CVE-2026-20796
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-20796.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-20796
Aliases
Downstream
Related
Published
2026-02-13T10:30:03.445Z
Modified
2026-07-15T01:48:56.895466988Z
Severity
  • 3.1 (Low) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N CVSS Calculator
Summary
Time-of-check time-of-use vulnerability in common teams API
Details

Mattermost versions 10.11.x <= 10.11.9 fail to properly validate channel membership at the time of data retrieval which allows a deactivated user to learn team names they should not have access to via a race condition in the /common_teams API endpoint.. Mattermost Advisory ID: MMSA-2025-00549

Database specific 
{
    "cna_assigner": "Mattermost",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/20xxx/CVE-2026-20796.json",
    "unresolved_ranges": [
        {
            "extracted_events": [
                {
                    "introduced": "10.11.0"
                },
                {
                    "last_affected": "10.11.9"
                }
            ],
            "source": "AFFECTED_FIELD"
        }
    ],
    "cwe_ids": [
        "CWE-367"
    ]
}
References

Affected packages

Git / github.com/mattermost/mattermost

Affected ranges

Type
GIT
Repo
https://github.com/mattermost/mattermost
Events
Introduced
5b955468ea1ea8b56c0fb10feb258a36a767d7bb
Fixed
ba27ba1f8cb1ffe2b1a79dc3d15a3ffa7de12fd7
Database specific 
{
    "cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
    "extracted_events": [
        {
            "introduced": "10.11.0"
        },
        {
            "fixed": "10.11.10"
        }
    ],
    "source": "CPE_RANGE"
}

Affected versions

@mattermost/client@10.*
@mattermost/client@10.11.0
@mattermost/types@10.*
@mattermost/types@10.11.0
mattermost-redux@10.*
mattermost-redux@10.11.0
v10.*
v10.11.0
v10.11.0-rc3
v10.11.1
v10.11.1-rc1
v10.11.2
v10.11.2-rc1
v10.11.2-rc2
v10.11.3
v10.11.4
v10.11.4-rc1
v10.11.4-rc2
v10.11.4-rc3
v10.11.5
v10.11.6
v10.11.7
v10.11.8
v10.11.9
v10.11.9-rc1

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-20796.json"