Discourse OAuth Social Login - Cross-site Scripting

Discourse versions prior to 3.5.0.beta6 contain a stored Cross-Site Scripting XSS vulnerability in the OAuth/social login functionality. The vulnerability is caused by lack of proper content security policy enforcement when processing social login failures,allowing remote attackers to inject and...

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...

CVE-2026-55704

Discourse is an open-source discussion platform. Prior o 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, users who were allowed to view a group’s activity, but were not permitted to see shared drafts, could still receive shared-draft entries through the group posts and group mentions endpoints. This...

CVE-2026-53960

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, hidden or otherwise unviewable first-post content was leaked as an excerpt in the publicly-served Q&A QAPage JSON-LD structured data, exposing it to any unauthenticated visitor and to search-engi...

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-2026-53960

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, hidden or otherwise unviewable first-post content was leaked as an excerpt in the publicly-served Q&A QAPage JSON-LD structured data, exposing it to any unauthenticated visitor and to search-engi...

CVE-2026-53960

Discourse leaked hidden first-post excerpts in publicly served QAPage JSON-LD structured data, accessible to unauthenticated visitors and search-engine crawlers. Fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0. No exploitation reported. CVSS 5.3 MEDIUM (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:...

CVE-2026-53960 Discourse: Hidden first-post excerpt is emitted in Q&A schema JSON-LD

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, hidden or otherwise unviewable first-post content was leaked as an excerpt in the publicly-served Q&A QAPage JSON-LD structured data, exposing it to any unauthenticated visitor and to search-engi...

EUVD-2026-60238

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, hidden or otherwise unviewable first-post content was leaked as an excerpt in the publicly-served Q&A QAPage JSON-LD structured data, exposing it to any unauthenticated visitor and to search-engi...

CVE-2026-53960 Discourse: Hidden first-post excerpt is emitted in Q&A schema JSON-LD

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, hidden or otherwise unviewable first-post content was leaked as an excerpt in the publicly-served Q&A QAPage JSON-LD structured data, exposing it to any unauthenticated visitor and to search-engi...

CVE-2026-55704 Discourse: Shared-draft titles and excerpts leak through group post serialization

Discourse is an open-source discussion platform. Prior o 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, users who were allowed to view a group’s activity, but were not permitted to see shared drafts, could still receive shared-draft entries through the group posts and group mentions endpoints. This...

CVE-2026-55704 Discourse: Shared-draft titles and excerpts leak through group post serialization

Discourse is an open-source discussion platform. Prior o 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, users who were allowed to view a group’s activity, but were not permitted to see shared drafts, could still receive shared-draft entries through the group posts and group mentions endpoints. This...

CVE-2026-55704

Discourse is an open-source discussion platform. Prior o 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, users who were allowed to view a group’s activity, but were not permitted to see shared drafts, could still receive shared-draft entries through the group posts and group mentions endpoints. This...

EUVD-2026-60237

Discourse is an open-source discussion platform. Prior o 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, users who were allowed to view a group’s activity, but were not permitted to see shared drafts, could still receive shared-draft entries through the group posts and group mentions endpoints. This...

CVE-2026-55704

Discourse serializes shared-draft topics and posts through the group posts and group mentions endpoints regardless of draft-view permissions, leaking unpublished draft titles and content to any group-activity viewer. Affected versions prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0 are fixed ...

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...

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: 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...