CVE-2026-19541 Details
Description
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to require re-entry of the stored client secret when validating an outgoing OAuth connection, which allows an authenticated user with permission to manage outgoing OAuth connections to obtain the secret via pointing the token URL at an attacker-controlled endpoint and triggering validation.. Mattermost Advisory ID: MMSA-2026-00761
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Oct 16, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://mattermost.com/security-updates | [email protected] | Vendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-201 | Insertion of Sensitive Information Into Sent Data | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| mattermost mattermost server | >= 11.7.0, < 11.7.11 >= 11.8.0, < 11.8.6 >= 11.9.0, < 11.9.2 >= 11.10.0, < 11.10.2 |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Oct 29, 2026 | Initial Analysis | [email protected] |
| Oct 16, 2026 | CVE Modified | CISA-ADP |
| Oct 16, 2026 | New CVE Received | [email protected] |