Improper Check for Unusual or Exceptional Conditions Affecting github.com/mattermost/mattermost/server/channels/app package, versions >=10.11.0-rc1 <10.11.15-rc1>=11.4.0-rc1 <11.4.5>=11.5.0-rc1 <11.5.3>=11.6.0-rc1 <11.6.1-rc1
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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Test your applications- Snyk IDSNYK-GOLANG-GITHUBCOMMATTERMOSTMATTERMOSTSERVERCHANNELSAPP-17117510
- published1 Jun 2026
- disclosed25 May 2026
- creditdaw10
Introduced: 25 May 2026
CVE-2026-4915 (opens in a new tab)How to fix?
Upgrade github.com/mattermost/mattermost/server/channels/app to version 10.11.15-rc1, 11.4.5, 11.5.3, 11.6.1-rc1 or higher.
Overview
github.com/mattermost/mattermost/server/channels/app is a private-cloud Slack alternative
Affected versions of this package are vulnerable to Improper Check for Unusual or Exceptional Conditions in the outgoing webhook process. An attacker can cause the server to terminate unexpectedly by sending a crafted webhook callback response containing a null attachment entry.