EUVD-2026-112505

Mattermost versions 11.9.x = 11.9.1, 11.8.x = 11.8.5, 11.7.x = 11.7.10 fail to validate the target post ID in the Agents plugin's mention reminder component, which allows an authenticated user who can post in a channel visible to a system administrator to cause the administrator's browser to send...

CVE-2026-93851

Mattermost versions 11.9.x = 11.9.1, 11.8.x = 11.8.5, 11.7.x = 11.7.10 fail to validate the target post ID in the Agents plugin's mention reminder component, which allows an authenticated user who can post in a channel visible to a system administrator to cause the administrator's browser to send...

CVE-2026-93851 Path traversal in Mattermost Agents plugin mention reminder allows plugin replacement via crafted post

Mattermost versions 11.9.x = 11.9.1, 11.8.x = 11.8.5, 11.7.x = 11.7.10 fail to validate the target post ID in the Agents plugin's mention reminder component, which allows an authenticated user who can post in a channel visible to a system administrator to cause the administrator's browser to send...

CVE-2026-93851: Mattermost: Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10 fail to validate the target post ID in the…

Mattermost versions 11.9.x = 11.9.1, 11.8.x = 11.8.5, 11.7.x = 11.7.10 fail to validate the target post ID in the Agents plugin's mention reminder component, which allows an authenticated user who can post in a channel visible to a system administrator to cause the administrator's browser to send...

CLSA-2026-1793007594 TuxCare security update for linkify-plugin-mention (1 CVE)

TuxCare rebuilt linkify-plugin-mention to address 1 CVE. Fixed in 4.1.3-tuxcare.1...

PT-2026-115519

Mattermost versions 11.10.x = 11.10.0, 11.9.x = 11.9.1, 11.8.x = 11.8.5, 11.7.x = 11.7.10 fail to cap the number and size of mention keys stored in a user's notification properties, and to bound the quadratic multibyte-keyword matching performed for each post, which allows an authenticated user t...

PT-2026-105076

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the topic small-action and nested-activity-log components interpolated the free-form action code who value into mention-link href attributes without URL encoding. A quote-bearing display name cou...

CVE-2026-100675

stoatchat versions before 0.15.5 contain a denial of service vulnerability in the acknowledgement worker that processes mass mention messages. Authenticated users can send five crafted role-mention messages to terminate all acknowledgement workers, disabling push notifications and mention badges...

CVE-2026-100675

Versions of stoatchat prior to 0.15.5 are susceptible to a denial of service vulnerability within the acknowledgement worker during the processing of mass mention messages. An authenticated user can trigger this by sending five specially crafted role-mention messages , which results in the termin...

EUVD-2026-87769

stoatchat versions before 0.15.5 contain a denial of service vulnerability in the acknowledgement worker that processes mass mention messages. Authenticated users can send five crafted role-mention messages to terminate all acknowledgement workers, disabling push notifications and mention badges...

PT-2026-99346

Name of the Vulnerable Software and Affected Versions stoatchat versions prior to 0.15.5 Description A denial of service issue exists in the acknowledgement worker responsible for processing mass mention messages. Authenticated users can send five specially crafted role-mention messages to...

CVE-2026-100675: Uncaught Exception

stoatchat versions before 0.15.5 contain a denial of service vulnerability in the acknowledgement worker that processes mass mention messages. Authenticated users can send five crafted role-mention messages to terminate all acknowledgement workers, disabling push notifications and mention badges...

CVE-2026-91119

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the topic small-action and nested-activity-log components interpolated the free-form actioncodewho value into mention-link href attributes without URL encoding. A quote-bearing display name could...

CVE-2026-91119 Discourse: Encode action_code_who in mention URLs

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the topic small-action and nested-activity-log components interpolated the free-form actioncodewho value into mention-link href attributes without URL encoding. A quote-bearing display name could...

CVE-2026-91119 Discourse: Encode action_code_who in mention URLs

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the topic small-action and nested-activity-log components interpolated the free-form actioncodewho value into mention-link href attributes without URL encoding. A quote-bearing display name could...

CVE-2026-91119 Discourse: Encode action_code_who in mention URLs

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the topic small-action and nested-activity-log components interpolated the free-form actioncodewho value into mention-link href attributes without URL encoding. A quote-bearing display name could...

EUVD-2026-86307

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the topic small-action and nested-activity-log components interpolated the free-form actioncodewho value into mention-link href attributes without URL encoding. A quote-bearing display name could...

CVE-2026-91119

The open-source discussion platform Discourse is vulnerable to stored HTML injection in versions prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0. The small-action and nested-activity-log components fail to perform URL encoding when interpolating the free-form action_code_who value into mentio...

PT-2026-98202

Name of the Vulnerable Software and Affected Versions Discourse versions prior to 2026.1.8 Discourse versions prior to 2026.6.3 Discourse versions prior to 2026.7.2 Discourse versions prior to 2026.8.0 Description The topic small-action and nested-activity-log components interpolate the free-form...

CVE-2026-91119: Improper Neutralization of Input During Web Page Generation

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the topic small-action and nested-activity-log components interpolated the free-form actioncodewho value into mention-link href attributes without URL encoding. A quote-bearing display name could...