Missing Authorization Affecting github.com/mattermost/mattermost/server/channels/app package, versions >=11.5.0-rc1 <11.5.2-rc3>=11.6.0-rc1 <11.6.0
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Start learning- Snyk IDSNYK-GOLANG-GITHUBCOMMATTERMOSTMATTERMOSTSERVERCHANNELSAPP-16873663
- published24 May 2026
- disclosed18 May 2026
- creditdaw10
Introduced: 18 May 2026
CVE-2026-5163 (opens in a new tab)How to fix?
Upgrade github.com/mattermost/mattermost/server/channels/app to version 11.5.2-rc3, 11.6.0 or higher.
Overview
github.com/mattermost/mattermost/server/channels/app is a private-cloud Slack alternative
Affected versions of this package are vulnerable to Missing Authorization via the post rewrite endpoint. An attacker can gain unauthorized access to the content of threads in private channels and direct messages by sending a crafted request.