BIT-DISCOURSE-2026-33251 Discourse has a Hidden Solved topics permission bypass

Discourse is an open-source discussion platform. Prior to versions 2026.3.0, 2026.2.1, and 2026.1.2, an authorization bypass vulnerability in hidden Solved topics may allow unauthorized users to accept or unaccept solutions. Versions 2026.3.0, 2026.2.1, and 2026.1.2 contain a patch. As a...

BIT-DISCOURSE-2026-32114 Discourse's unscoped status lookups leak restricted metadata

Discourse is an open-source discussion platform. Prior to versions 2026.3.0, 2026.2.1, and 2026.1.2, there is an Insecure Direct Object Reference IDOR vulnerability that allows any authenticated user to access metadata about AI personas, features, and LLM models by providing their identifiers. Th...

BIT-DISCOURSE-2026-31869 Discourse: Composer mentions endpoint leaks hidden group membership through PM `allowed_names` check

Discourse is an open-source discussion platform. Prior to versions 2026.3.0, 2026.2.1, and 2026.1.2, the ComposerControllermentions endpoint reveals hidden group membership to any authenticated user who can message the group. By supplying allowednames referencing a hidden-membership group and...

BIT-DISCOURSE-2026-31805 Discourse has a poll authorization bypass via post_id array parameter

Discourse is an open-source discussion platform. Prior to versions 2026.3.0, 2026.2.1, and 2026.1.2, an authorization bypass in the poll plugin allowed authenticated users to vote on, remove votes from, or toggle the open/closed status of polls they did not have access to. By passing postid as an...

BIT-DISCOURSE-2026-30891 Discourse hasUnauthorized Exposure of Private User Action Types

Discourse is an open-source discussion platform. Prior to versions 2026.3.0, 2026.2.1, and 2026.1.2, a user could access another user's private activity due to insufficient authorization checks in the user actions endpoint. Versions 2026.3.0, 2026.2.1, and 2026.1.2 contain a patch...

BIT-DISCOURSE-2026-30889 Discourse has Unauthorized Post Data Exposure in discourse-user-notes

Discourse is an open-source discussion platform. Prior to versions 2026.3.0, 2026.2.1, and 2026.1.2, a moderator could exploit insufficient authorization checks to access metadata of posts they should not have permission to view. Versions 2026.3.0, 2026.2.1, and 2026.1.2 contain a patch...

BIT-DISCOURSE-2026-30888 Discourse has moderator privilege escalation via arbitrary post_id in suspend/silence endpoint

Discourse is an open-source discussion platform. Versions prior to 2026.3.0, 2026.2.1, and 2026.1.2 allow a moderator to edit site policy documents ToS, guidelines, privacy policy that they are explicitly prohibited from modifying. Versions 2026.3.0, 2026.2.1, and 2026.1.2 contain a patch. No kno...

BIT-DISCOURSE-2026-29072 Discourse missing permission check for policy creation in discourse-policy

Discourse is an open-source discussion platform. Prior to versions 2026.3.0, 2026.2.1, and 2026.1.2, users who do not belong to the allowed policy creation groups can create functional policy acceptance widgets in posts under the right conditions. Versions 2026.3.0, 2026.2.1, and 2026.1.2 contain...

BIT-DISCOURSE-2026-28282 Discourse vulnerable to group membership addition permission bypass via discourse-policy plugin

Discourse is an open-source discussion platform. Versions prior to 2026.3.0, 2026.2.1, and 2026.1.2 have a security flaw in the discourse-policy plugin which allowed a user with policy creation permission to gain membership access to any private/restricted groups. Once membership to a...

BIT-DISCOURSE-2026-27936 Discourse discloses restricted post-action counts to non-privileged users

Discourse is an open-source discussion platform. Prior to versions 2026.3.0, 2026.2.1, and 2026.1.2, a restriction bypass allows restricted post action counts to be disclosed to non-privileged users through a carefully crafted request. Versions 2026.3.0, 2026.2.1, and 2026.1.2 contain a patch. No...

BIT-DISCOURSE-2026-27935 Discourse leaks private topic metadata to non-authorized users

Discourse is an open-source discussion platform. Versions prior to 2026.3.0, 2026.2.1, and 2026.1.2 have a vulnerability in an API endpoint that discloses private topic metadata of admin users to moderator users even if the moderators do not have access to the private topics. Versions 2026.3.0,...

BIT-DISCOURSE-2026-27934 Discourse leaks private topic title and post excerpt via user action API endpoint

Discourse is an open-source discussion platform. Versions prior to 2026.3.0, 2026.2.1, and 2026.1.2 have a lack of visibility checks with a user action API endpoint that results in disclosure of the title and post excerpt to unauthorized users, leading to information disclosure. Versions 2026.3.0...

BIT-DISCOURSE-2026-27740 Discourse has Stored XSS in AI Triage Automation

Discourse is an open-source discussion platform. Versions prior to 2026.3.0, 2026.2.1, and 2026.1.2 have a cross-site scripting vulnerability that arises because the system trusts the raw output from an AI Large Language Model LLM and renders it using htmlSafe in the Review Queue interface withou...

BIT-DISCOURSE-2026-27570 Discourse Vulnerable to Stored XSS via Shared AI Conversation Onebox

Discourse is an open-source discussion platform. Prior to versions 2026.3.0, 2026.2.1, and 2026.1.2, the onebox method in the SharedAiConversation model renders the conversation title directly into HTML without proper sanitization. Versions 2026.3.0, 2026.2.1, and 2026.1.2 contain a patch. As a...

BIT-DISCOURSE-2026-27491 Discourse has a bypass of official warnings messages by non-staff users

Discourse is an open-source discussion platform. Prior to versions 2026.3.0, 2026.2.1, and 2026.1.2, a type coercion issue in a post actions API endpoint allowed non-staff users to issue warnings to other users. Warnings are a staff-only moderation feature. The vulnerability required the attacker...

BIT-DISCOURSE-2026-27454 Discourse has check revision visibility on posts endpoint

Discourse is an open-source discussion platform. Prior to versions 2026.3.0, 2026.2.1, and 2026.1.2, requesting /posts/:id.json?version=X bypassed authorization checks on post revisions. The displaypost method called post.revertto directly without verifying whether the revision was hidden or if t...

BIT-DISCOURSE-2026-27166 Discourse vulnerable to HTML injection via prohibited iframe URLs

Discourse is an open source discussion platform. Prior to versions 2026.3.0, 2026.2.1 and 2026.1.2, insufficient cleanup in the default Codepen allowed iframes value allows an attacker to trick a user into changing the URL of the main page. This issue has been fixed in versions 2026.3.0, 2026.2.1...

CVE-2026-30888

Discourse is an open-source discussion platform. Versions prior to 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 allow a moderator to edit site policy documents ToS, guidelines, privacy policy that they are explicitly prohibited from modifying. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 conta...

CVE-2026-33423

Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, staff can modify any user's group notification level. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. No known workarounds are available...

CVE-2026-33427

Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, an unauthenticated attacker can cause a legitimate Discourse authorization page to display an attacker-controlled domain, facilitating social engineering attacks against users. Versions...