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 apply the internal-connection filter to OAuth endpoint requests, which allows a System Administrator to make the server issue requests to internal network addresses and read the responses via the configured OAuth token and userinfo endpoints.. Mattermost Advisory ID: MMSA-2026-00776
Metrics
Affected Vendors & Products
References
| Link | Providers |
|---|---|
| https://mattermost.com/security-updates |
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History
Wed, 07 Oct 2026 17:00:00 +0000
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Mattermost mattermost Server
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| CPEs | cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Mattermost mattermost Server
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Wed, 23 Sep 2026 14:30:00 +0000
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| Metrics |
ssvc
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Tue, 22 Sep 2026 21:45:00 +0000
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Mattermost
Mattermost mattermost |
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| Vendors & Products |
Mattermost
Mattermost mattermost |
Tue, 22 Sep 2026 20:45:00 +0000
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| 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 apply the internal-connection filter to OAuth endpoint requests, which allows a System Administrator to make the server issue requests to internal network addresses and read the responses via the configured OAuth token and userinfo endpoints.. Mattermost Advisory ID: MMSA-2026-00776 | |
| Title | Mattermost server-side request forgery via OAuth endpoints configurable by a System Administrator | |
| Weaknesses | CWE-918 | |
| References |
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| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: Mattermost
Published: 2026-09-22T20:34:20.872Z
Updated: 2026-09-23T13:10:47.754Z
Reserved: 2026-09-22T19:59:57.887Z
Link: CVE-2026-96259
Updated: 2026-09-23T13:10:41.631Z
Status : Analyzed
Published: 2026-09-22T21:17:34.910
Modified: 2026-10-07T16:41:14.847
Link: CVE-2026-96259
No data.