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Mattermost server-side request forgery via OAuth endpoints configurable by a System Administrator

CVSS 3.1 5.5 MEDIUMCheck source for fixed versionsKEV status unknown

cve-program · CVE-2026-96259

Published

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

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CVE-2026-96259 · CVE overview and exploitation status

cve-program · CVE-2026-96259

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ChangeIntel

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Sources read 12 Nov 19:39 UTC · 274 of 275 readable · 272 fully read · documentation 469/469 current