CVE-2026-96259
Last modified
CVE-2026-96259 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. 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. EPSS estimates a 0.26% chance of exploitation in the next 30 days.
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
Metrics
Weakness Enumeration
Affected Software
Source: CNA advisory (CVE.org). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| Mattermost | Mattermost | >= 11.9.0, <= 11.9.1; >= 11.8.0, <= 11.8.5; >= 11.7.0, <= 11.7.10; >= 11.10.0, <= 11.10.1 |
References
Timeline
- Published
- Last Modified
- Status
- Awaiting Analysis
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