Improper Check for Unusual or Exceptional Conditions

Overview 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...

Improper Check for Unusual or Exceptional Conditions

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 b...

CVE-2026-4915

Mattermost is affected in CVE-2026-4915 across multiple release streams (11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x

PT-2026-43013

Name of the Vulnerable Software and Affected Versions Mattermost version 11.6.0 Mattermost version 11.5.3 Mattermost version 11.4.4 Mattermost version 10.11.14 Description An issue exists where the system fails to filter nil elements from outgoing webhook attachment payloads before processing. Th...