CVE-2026-9824

Mattermost v11.7.x ≤ 11.7.2, v11.6.x ≤ 11.6.4, and v10.11.x ≤ 10.11.19 are affected by CVE-2026-9824 due to a missing check of the manage_shared_channels permission in the /share-channel autocomplete handler. This allows an authenticated user without that permission to enumerate remote cluster co...

CVE-2026-8823 User Manager can demote bot accounts to guest without bot-management permission

Mattermost versions 11.7.x = 11.7.0, 10.11.x = 10.11.17 fail to validate bot targets when demoting users to guests which allows a lower-privileged administrator to degrade arbitrary bot accounts via the standard demote-user API.. Mattermost Advisory ID: MMSA-2026-00669...

PT-2026-42745

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 Improper validation of file ownership and access control in the Boards API allows an authenticated user to access and downloa...

PT-2026-42748

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 Insufficient input validation in the GitHub plugin API request handlers allows an authenticated attacker to cause a denial of...

CVE-2026-6333 SSRF via Host Header Spoofing in Custom Slash Commands

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13 fail to validate the Host header when constructing response URLs for custom slash commands which allows an authenticated attacker to redirect slash command responses to an attacker-controlled server via a spoofed Host header.. Mattermost...

CVE-2026-6345 Prevent password disclosure and force reset during Slack import

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail prevent disclosure of created user password which allows a malicious attacker to impersonate a user via the use of some of those passwords.. Mattermost Advisory ID: MMSA-2026-00614...

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...

SUSE CVE-2026-26233

Mattermost versions 11.4.x = 11.4.0, 11.3.x = 11.3.1, 11.2.x = 11.2.3, 10.11.x = 10.11.11 fail to rate limit login requests which allows unauthenticated remote attackers to cause denial of service server crash and restart via HTTP/2 single packet attack with 100+ parallel login requests...

EUVD-2026-12516

Mattermost versions 10.11.x = 10.11.10 Fail to invalidate cached permalink preview data when a user loses channel access which allows the user to continue viewing private channel content via previously cached permalink previews until cache reset or relogin.. Mattermost Advisory ID: MMSA-2026-0058...

EUVD-2026-12415

Mattermost versions 11.3.x = 11.3.0 fail to preserve the redacted state of burn-on-read posts during deletion which allows channel members to access unrevealed burn-on-read message contents via the WebSocket post deletion event.. Mattermost Advisory ID: MMSA-2026-00579...

CVE-2026-25783

Mattermost versions 11.3.x = 11.3.0, 11.2.x = 11.2.2, 10.11.x = 10.11.10 fail to properly validate User-Agent header tokens which allows an authenticated attacker to cause a request panic via a specially crafted User-Agent header. Mattermost Advisory ID: MMSA-2026-00586...

CVE-2026-26246 Memory Exhaustion via Malformed PSD File Upload

Mattermost versions 11.3.x = 11.3.0, 11.2.x = 11.2.2, 10.11.x = 10.11.10 fail to bound memory allocation when processing PSD image files which allows an authenticated attacker to cause server memory exhaustion and denial of service via uploading a specially crafted PSD file. Mattermost Advisory I...

PT-2026-25809

Mattermost versions 11.3.x = 11.3.0, 11.2.x = 11.2.2, 10.11.x = 10.11.10 fail to handle incorrectly reported array lengths which allows malicious user to cause OOM errors and crash the server via sending corrupted msgpack frames within websocket messages to calls plugin. Mattermost Advisory ID:...

Time-of-check Time-of-use (TOCTOU) Race Condition

Overview Affected versions of this package are vulnerable to Time-of-check Time-of-use TOCTOU Race Condition via a race condition in the /commonteams API endpoint. An attacker can gain unauthorized access to team names by exploiting the timing of channel membership validation during data retrieva...

EUVD-2025-186557

Mattermost versions 11.0 fail to properly enforce the "Allow users to view archived channels" setting which allows regular users to access archived channel content and files via the "Open in Channel" functionality from followed threads...

EUVD-2022-42571

Malicious code in bioql PyPI...

EUVD-2025-29172

Malicious code in bioql PyPI...

EUVD-2022-6283

Malicious code in bioql PyPI...

EUVD-2024-38242

Malicious code in bioql PyPI...

EUVD-2024-2498

Malicious code in bioql PyPI...