Vulnerabilities (CVE)

Filtered by vendor Discourse Subscribe
Filtered by product Discourse
Total 263 CVE
CVE Vendors Products Updated CVSS v2 CVSS v3
CVE-2026-31805 1 Discourse 1 Discourse 2026-06-17 N/A 5.3 MEDIUM
Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 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 post_id as an array (e.g. post_id[]=&post_id[]=), the authorization check resolves to the accessible post while the poll lookup resolves to a different post's poll. This affects the vote, remove_vote, and toggle_status endpoints in DiscoursePoll::PollsController. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch.
CVE-2026-30891 1 Discourse 1 Discourse 2026-06-17 N/A 6.5 MEDIUM
Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 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-latest.1, 2026.2.1, and 2026.1.2 contain a patch.
CVE-2026-30889 1 Discourse 1 Discourse 2026-06-17 N/A 4.9 MEDIUM
Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 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-latest.1, 2026.2.1, and 2026.1.2 contain a patch.
CVE-2026-30888 1 Discourse 1 Discourse 2026-06-17 N/A 2.2 LOW
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 contain a patch. No known workarounds are available.
CVE-2026-29072 1 Discourse 1 Discourse 2026-06-17 N/A 7.5 HIGH
Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 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-latest.1, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, disable the discourse-policy plugin by disabling the `policy_enabled` site setting.
CVE-2026-28282 1 Discourse 1 Discourse 2026-06-17 N/A 6.5 MEDIUM
Discourse is an open-source discussion platform. Versions prior to 2026.3.0-latest.1, 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 private/restricted group has been obtained, the user will be able to read private topics that only the group has access to. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, review all policies for the use of `add-users-to-group` and temporarily remove the attribute from the policy. Alternatively, disable the discourse-policy plugin by disabling the `policy_enabled` site setting.
CVE-2026-28227 1 Discourse 1 Discourse 2026-06-17 N/A 2.7 LOW
Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, TL4 users can publish topics into staff-only categories via the `publish_to_category` topic timer, bypassing authorization checks. Versions 2025.12.2, 2026.1.1, and 2026.2.0 patch the issue. No known workarounds are available.
CVE-2026-28219 1 Discourse 1 Discourse 2026-06-17 N/A 4.3 MEDIUM
Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, an improper authorization check in the topic management logic allows authenticated users to modify privileged attributes of their topics. By manipulating specific parameters in a PUT or POST request, a regular user can elevate a topic’s status to a site-wide notice or banner, bypassing intended administrative restrictions. Versions 2025.12.2, 2026.1.1, and 2026.2.0 patch the issue. There are no practical workarounds to prevent this behavior other than applying the security patch. Administrators concerned about unauthorized promotions should audit recent changes to site banners and global notices until the fix is deployed.
CVE-2026-28218 1 Discourse 1 Discourse 2026-06-17 N/A 5.4 MEDIUM
Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, fail-open access control in Data Explorer plugin allows any authenticated user to execute SQL queries that have no explicit group assignments, including built-in system queries. Versions 2025.12.2, 2026.1.1, and 2026.2.0 patch the issue. As a workaround, either explicitly set group permissions on each Data Explorer query that doesn't have permissions, or disable discourse-data-explorer plugin.
CVE-2026-27936 1 Discourse 1 Discourse 2026-06-17 N/A 5.3 MEDIUM
Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 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-latest.1, 2026.2.1, and 2026.1.2 contain a patch. No known workarounds are available.
CVE-2026-27935 1 Discourse 1 Discourse 2026-06-17 N/A 6.5 MEDIUM
Discourse is an open-source discussion platform. Versions prior to 2026.3.0-latest.1, 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-latest.1, 2026.2.1, and 2026.1.2 contain a patch. No known workarounds are available.
CVE-2026-27934 1 Discourse 1 Discourse 2026-06-17 N/A 7.5 HIGH
Discourse is an open-source discussion platform. Versions prior to 2026.3.0-latest.1, 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-latest.1, 2026.2.1, and 2026.1.2 contain a patch. No known workarounds are available.
CVE-2026-27740 1 Discourse 1 Discourse 2026-06-17 N/A 6.1 MEDIUM
Discourse is an open-source discussion platform. Versions prior to 2026.3.0-latest.1, 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 without adequate sanitization. A malicious attacker can use valid Prompt Injection techniques to force the AI to return a malicious payload (e.g., tags). When a Staff member (Admin/Moderator) views the flagged post in the Review Queue, the payload executes. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, temporarily disable AI triage automation scripts.
CVE-2026-27570 1 Discourse 1 Discourse 2026-06-17 N/A 6.1 MEDIUM
Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 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-latest.1, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, tighten access by changing the `ai_bot_public_sharing_allowed_groups` site setting.
CVE-2026-27491 1 Discourse 1 Discourse 2026-06-17 N/A 4.3 MEDIUM
Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 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 to be a logged-in user and to send a specifically crafted request. No data exposure or privilege escalation beyond the ability to create unauthorized user warnings was possible. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. No known workarounds are available.
CVE-2026-27481 1 Discourse 1 Discourse 2026-06-17 N/A 5.3 MEDIUM
Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.3, 2026.2.0-latest to before 2026.2.2, and 2026.3.0-latest to before 2026.3.0, an authorization bypass vulnerability allows unauthenticated or unauthorized users to view hidden (staff-only) tags and its associated data. All Discourse instances with tagging enabled and staff-only tag groups configured are impacted. This issue has been patched in versions 2026.1.3, 2026.2.2, and 2026.3.0.
CVE-2026-27454 1 Discourse 1 Discourse 2026-06-17 N/A 5.3 MEDIUM
Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, requesting /posts/:id.json?version=X bypassed authorization checks on post revisions. The display_post method called post.revert_to directly without verifying whether the revision was hidden or if the user had permission to view edit history. This meant hidden revisions (intentionally concealed by staff) could be read by any user by simply enumerating version numbers. Starting in versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, Discourse looks up the PostRevision and call guardian.ensure_can_see! before reverting, consistent with how the /posts/:id/revisions/:revision endpoint already authorizes access. No known workarounds are available.
CVE-2026-27166 1 Discourse 1 Discourse 2026-06-17 N/A 4.1 MEDIUM
Discourse is an open source discussion platform. Prior to versions 2026.3.0-latest.1, 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-latest.1, 2026.2.1 and 2026.1.2. To workaround this issue, remove Codepen from the list of allowed iframes.
CVE-2026-27162 1 Discourse 1 Discourse 2026-06-17 N/A 4.9 MEDIUM
Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, `posts_nearby` was checking topic access but then returning all posts regardless of type, including whispers that should only be visible to whisperers. Use `Post.secured(guardian)` to properly filter post types based on user permissions. Versions 2025.12.2, 2026.1.1, and 2026.2.0 patch the issue. No known workarounds are available.
CVE-2026-27154 1 Discourse 1 Discourse 2026-06-17 N/A 6.1 MEDIUM
Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, a user full name can be evaluated as raw HTML when the following settings are set: `display_name_on_posts` => true; and `prioritize_username_in_ux` => false. Editing a post of a malicious user would trigger an XSS. Versions 2025.12.2, 2026.1.1, and 2026.2.0 patch the issue. No known workarounds are available.