EUVD-2026-60236

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, an unauthenticated attacker could send a single request with a crafted colorschemeid or darkschemeid cookie to inject arbitrary HTML into a Discourse page. Because the cookie value was rendered...

CVE-2026-55674

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, an unauthenticated attacker could send a single request with a crafted colorschemeid or darkschemeid cookie to inject arbitrary HTML into a Discourse page. Because the cookie value was rendered...

CVE-2026-55674 Discourse: Cache poisoning/XSS via color scheme cookies

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, an unauthenticated attacker could send a single request with a crafted colorschemeid or darkschemeid cookie to inject arbitrary HTML into a Discourse page. Because the cookie value was rendered...

CVE-2026-55674 Discourse: Cache poisoning/XSS via color scheme cookies

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, an unauthenticated attacker could send a single request with a crafted colorschemeid or darkschemeid cookie to inject arbitrary HTML into a Discourse page. Because the cookie value was rendered...

CVE-2026-55674

Discourse versions before 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0 render the unescaped color_scheme_id/dark_scheme_id cookie value into a color scheme tag, allowing an unauthenticated attacker to break out of the attribute, bypass Discourse's nonce-based CSP, and execute arbitrary JavaScript i...

CVE-2026-59829

CVE-2026-59829 affects Discourse sites with category group moderation enabled: the review queue could expose flag-related private message excerpts to category group moderators lacking authorization to read them. CVSS 4.3 (MEDIUM), confidentiality-only impact. Fixed in versions 2026.1.6, 2026.5.2,...

CVE-2026-59829 Discourse: Review queue exposes flag-related private message excerpts to category group moderators

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.1, on sites with category group moderation enabled, the review queue could include an excerpt and permalink of the private message attached to a flag, even when the reviewing category moderator was...

CVE-2026-59829 Discourse: Review queue exposes flag-related private message excerpts to category group moderators

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.1, on sites with category group moderation enabled, the review queue could include an excerpt and permalink of the private message attached to a flag, even when the reviewing category moderator was...

EUVD-2026-60235

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.1, on sites with category group moderation enabled, the review queue could include an excerpt and permalink of the private message attached to a flag, even when the reviewing category moderator was...

CVE-2026-59829

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.1, on sites with category group moderation enabled, the review queue could include an excerpt and permalink of the private message attached to a flag, even when the reviewing category moderator was...

BIT-DISCOURSE-2026-72732 Discourse: Templates endpoint exposes hidden tag names

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, the discoursetemplates endpoint exposed hidden tag names because DiscourseTemplates::TemplatesSerializer in plugins/discourse-templates/app/serializers/discoursetemplates/templatesserializer.rb d...

BIT-DISCOURSE-2026-72731 Discourse: Strip SQL comments and use non-recursive parameter interpolation in Data Explorer

Discourse is an open-source discussion platform. From 2026.1.0 until 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0, anyone able to run a parameterized Data Explorer query, including non-staff members of a group a query is shared with, could craft parameter values that escaped the intended query and...

BIT-DISCOURSE-2026-72730 Discourse: Stored XSS chat-transcript username unescaped in Rich Text Editor

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, the Rich Text Editor rendered a chat-transcript username as HTML, allowing stored cross-site scripting. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0...

BIT-DISCOURSE-2026-72729 Discourse: Stored XSS in discourse-local-dates plugin

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, the discourse-local-dates plugin rendered crafted local-date format data as HTML on sites with a modified or disabled default Content Security Policy. This issue is fixed in versions 2026.1.6,...

BIT-DISCOURSE-2026-72728 Discourse: Onebox iframe origin allowlist enforces URL authority boundary

Discourse is an open-source discussion platform. Prior to 2026.1.7, an authenticated user could submit specially formed URLs that bypassed the Onebox allowlist and embedded malicious content in a site. This issue is fixed in versions 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0...

BIT-DISCOURSE-2026-72727 Discourse: Stored XSS in the moderation review queue

Discourse is an open-source discussion platform. Prior to 026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, a low-privileged user could place crafted content in the moderation review queue that executed stored cross-site scripting when a moderator viewed it on a site with a modified or disabled default...

BIT-DISCOURSE-2026-72726 Discourse: Unauthorized eavesdropping on private AI bot conversations.

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, an authenticated user could eavesdrop on private AI bot conversations through the AI bot reply stream. The issue is fixed in 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0...

BIT-DISCOURSE-2026-72725 Discourse: Stored XSS in staff action logs injects staff UI

Discourse is an open-source discussion platform. Prior to 2026.1.6, the staff action log model rendered unescaped previous and new value fields that could inject stored cross-site scripting into the staff interface. The issue is fixed in 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0...

BIT-DISCOURSE-2026-72724 Discourse: Private Chat Threat Message Disclosure via Chat Onebox Channel/Threat ID Mismatch

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, plugins/chat/lib/chat/oneboxhandler.rb resolves Chat::Thread by route threadid independently of the route channelid before checking whether the user can preview the selected chat channel. An...

BIT-DISCOURSE-2026-72723 Discourse: Anonymous sidebar serialization exposes descriptions of category-restricted tags

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, SiteSerializer.anonymousdefaultnavigationmenutags serializes tags from SiteSetting.defaultnavigationmenutags without applying DiscourseTagging.filtervisible for the anonymous viewer. An...