Authorization Bypass Through User-Controlled Key

Overview github.com/mattermost/mattermost/server/v8/channels/api4 is a platform for secure collaboration across the entire software development lifecycle Affected versions of this package are vulnerable to Authorization Bypass Through User-Controlled Key via the incoming webhook process. An...

Authorization Bypass Through User-Controlled Key

Overview github.com/mattermost/mattermost/server/channels/app is a private-cloud Slack alternative Affected versions of this package are vulnerable to Authorization Bypass Through User-Controlled Key via the incoming webhook process. An attacker can impersonate another user and create posts or...

Authorization Bypass Through User-Controlled Key

Overview Affected versions of this package are vulnerable to Authorization Bypass Through User-Controlled Key via the incoming webhook process. An attacker can impersonate another user and create posts or direct messages attributed to them by crafting specific webhook configurations and payloads...

Authorization Bypass Through User-Controlled Key

Overview Affected versions of this package are vulnerable to Authorization Bypass Through User-Controlled Key via the incoming webhook process. An attacker can impersonate another user and create posts or direct messages attributed to them by crafting specific webhook configurations and payloads...

EUVD-2026-43308

Mattermost versions 11.7.x = 11.7.2, 11.6.x = 11.6.4, 10.11.x = 10.11.19 fail to validate that an assigned incoming webhook user has access to the target team or channel, which allows a requester with webhook management permissions to create posts or direct messages attributed to another user via...

CVE-2026-9708 Incoming webhook user attribution via unvalidated webhook owner

Mattermost versions 11.7.x = 11.7.2, 11.6.x = 11.6.4, 10.11.x = 10.11.19 fail to validate that an assigned incoming webhook user has access to the target team or channel, which allows a requester with webhook management permissions to create posts or direct messages attributed to another user via...

CVE-2026-9708

Mattermost vulnerable versions (11.7.x <= 11.7.2, 11.6.x <= 11.6.4, 10.11.x

CVE-2026-9708 Incoming webhook user attribution via unvalidated webhook owner

Mattermost versions 11.7.x = 11.7.2, 11.6.x = 11.6.4, 10.11.x = 10.11.19 fail to validate that an assigned incoming webhook user has access to the target team or channel, which allows a requester with webhook management permissions to create posts or direct messages attributed to another user via...

PT-2026-57664

Mattermost versions 11.7.x = 11.7.2, 11.6.x = 11.6.4, 10.11.x = 10.11.19 fail to validate that an assigned incoming webhook user has access to the target team or channel, which allows a requester with webhook management permissions to create posts or direct messages attributed to another user via...

CVE-2026-9708: Authorization Bypass Through User-Controlled Key

Mattermost versions 11.7.x = 11.7.2, 11.6.x = 11.6.4, 10.11.x = 10.11.19 fail to validate that an assigned incoming webhook user has access to the target team or channel, which allows a requester with webhook management permissions to create posts or direct messages attributed to another user via...

EUVD-2019-11400

Malware in sbrugna...

CVE-2025-1521

CVE-2025-1521 concerns PostHog's slack_incoming_webhook processing. The vulnerability stems from inadequate validation of a URI before accessing resources, enabling a network-based SSRF that can disclose sensitive information and potentially execute code in the service account context. The initia...

CVE-2023-2783

Mattermost Apps Framework fails to verify that a secret provided in the incoming webhook request allowing an attacker to modify the contents of the post sent by the Apps...

CVE-2019-20863

An issue was discovered in Mattermost Server before 5.13.0. Incoming webhook creation is not properly restricted...

Design/Logic Flaw

An issue was discovered in Mattermost Server before 5.13.0. Incoming webhook creation is not properly restricted...

CVE-2019-20863

An issue was discovered in Mattermost Server before 5.13.0. Incoming webhook creation is not properly restricted...

CVE-2019-20863

An issue was discovered in Mattermost Server before 5.13.0. Incoming webhook creation is not properly restricted...

CVE-2019-20863: Undefined Security Weakness

An issue was discovered in Mattermost Server before 5.13.0. Incoming webhook creation is not properly restricted...

PT-2020-10826

Name of the Vulnerable Software and Affected Versions Mattermost Server versions prior to 5.13.0 Description An issue was discovered where incoming webhook creation is not properly restricted. Recommendations For versions prior to 5.13.0, update to version 5.13.0 or later to resolve the issue...