EUVD-2026-30774

Dify version 1.14.1 and prior contain an authorization bypass vulnerability in the file preview endpoint that allows any authenticated user to read up to 3,000 characters of any uploaded document across all tenants and workspaces using only the file's UUID. Attackers can access the...

Improper Authorization

Overview wwbn/avideo is an Audio and Video Platform or simply "A Video Platform". Affected versions of this package are vulnerable to Improper Authorization via the mention.json.php process. An attacker can enumerate user information by sending unauthenticated requests that match the required inp...

Incorrect Authorization

Overview github.com/mattermost/mattermost-plugin-playbooks/server/app is a package for reliable and repeatable processes using checklists, automation, and retrospectives Affected versions of this package are vulnerable to Incorrect Authorization via the PUT API endpoint when updating playbooks. A...

Missing Authorization

Overview 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. Remediation Upgrade...

Missing Authorization

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...

Missing Authorization

Overview Affected versions of this package are vulnerable to Missing Authorization via the post update and patch API endpoints. An attacker can modify existing posts despite lacking posting privileges by sending crafted API requests. Remediation Upgrade...

GHSA-8R89-8W26-CQ32 Mattermost doesn't verify channel membership when processing AI-assisted message rewrites

Mattermost versions 11.5.x = 11.5.1 fail to verify channel membership when processing AI-assisted message rewrites which allows an authenticated attacker to read the content of threads in private channels and direct messages they do not have access to via a crafted request to the post rewrite...

Mattermost doesn't verify channel membership when processing AI-assisted message rewrites

Mattermost versions 11.5.x = 11.5.1 fail to verify channel membership when processing AI-assisted message rewrites which allows an authenticated attacker to read the content of threads in private channels and direct messages they do not have access to via a crafted request to the post rewrite...

GHSA-XVCX-MGPC-5XH3 Mattermost doesn't validate the X-Requested-With header on the burn-on-read reveal endpoint

Mattermost versions 11.5.x = 11.5.1, 11.4.x = 11.4.3 fail to validate the X-Requested-With header on the burn-on-read reveal endpoint which allows an authenticated channel member to force the reveal of a burn-on-read message without recipient consent via a crafted Markdown image tag.. Mattermost...

Allocation of Resources Without Limits or Throttling

Overview Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling via the start meeting API endpoint when the size of the request body is not limited. An attacker can exhaust system resources or disrupt service availability by sending crafted...

GHSA-M3P3-8FRQ-Q7QH Mattermost doesn't limit the size of the request body on the start meeting API endpoint

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to limit the size of the request body on the start meeting API endpoint, which allows an authenticated attacker to cause resource exhaustion or denial of service via a crafted oversized HTTP POST request to...

Mattermost doesn't limit the size of the request body on the start meeting API endpoint

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to limit the size of the request body on the start meeting API endpoint, which allows an authenticated attacker to cause resource exhaustion or denial of service via a crafted oversized HTTP POST request to...

GHSA-V549-XX3C-6PC8 Mattermost doesn't check the create_post channel permission during post edit operations

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to check the createpost channel permission during post edit operations which allows an authenticated attacker with revoked posting privileges to modify their existing posts via direct API requests to the post update and...

Mattermost doesn't check the create_post channel permission during post edit operations

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to check the createpost channel permission during post edit operations which allows an authenticated attacker with revoked posting privileges to modify their existing posts via direct API requests to the post update and...

CVE-2026-5163

Mattermost versions 11.5.x = 11.5.1 fail to verify channel membership when processing AI-assisted message rewrites which allows an authenticated attacker to read the content of threads in private channels and direct messages they do not have access to via a crafted request to the post rewrite...

EUVD-2026-30751

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to check public/private permissions which allows members without these permissions to access public playbooks via /get.. Mattermost Advisory ID: MMSA-2026-00591...

CVE-2026-6343

Mattermost Playbooks plugin vulnerability CVE-2026-6343 affects Mattermost versions 11.5.x up to 11.5.1, 11.4.x up to 11.4.3, and 10.11.x up to 10.11.13. The issue is that public/private permissions are not checked, allowing members without required permissions to access public playbooks via endp...

CVE-2026-5163

Mattermost versions 11.5.x = 11.5.1 fail to verify channel membership when processing AI-assisted message rewrites which allows an authenticated attacker to read the content of threads in private channels and direct messages they do not have access to via a crafted request to the post rewrite...

CVE-2026-5163

Mattermost 11.5.x prior to 11.5.2 (up to 11.5.1 affected) fails to verify channel membership when processing AI-assisted message rewrites, allowing an authenticated user to read content from threads in private channels and direct messages they should not access via a crafted request to the post r...

CVE-2026-5163 Missing authorization check in AI message rewrite endpoint allows access to private thread content

Mattermost versions 11.5.x = 11.5.1 fail to verify channel membership when processing AI-assisted message rewrites which allows an authenticated attacker to read the content of threads in private channels and direct messages they do not have access to via a crafted request to the post rewrite...