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...

Discourse Backup File Disclosure Via Default Nginx Configuration

Discourse is an open source platform for community discussion. This vulnerability only impacts Discourse instances configured to use FileStore--LocalStore which means uploads and backups are stored locally on disk. If an attacker knows the name of the Discourse backup file, the attacker can trick...

CVE-2026-59828

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, post revisions that should be hidden from regular users could be leaked through visible diffs on adjacent revisions serialized by PostRevisionSerializer. This issue is fixed in versions 2026.6.0,...

CVE-2026-55424

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, a topic "featured link" was not sufficiently normalized and escaped before being rendered in the topic list, allowing a user who can set a featured link to inject JavaScript when default Content...

CVE-2026-46413

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, regular users could route direct S3 multipart uploads through ExternalUploadManager into the admin backup store. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5...

CVE-2026-53961

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, the AWS SES bounce webhook at POST /webhooks/aws verified that SNS messages were signed by Amazon but did not bind them to trusted TopicArn values, allowing any AWS account holder to publish...

CVE-2026-53962

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, insufficient SVG sanitization in upload and user avatar handling could lead to cross-site scripting when a user visited specific URLs that are not normally part of community browsing. This issue ...

CVE-2026-49256

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, restricted tag and tag-group names attached to publicly readable categories as allowedtags, allowedtaggroups, or required tag groups could leak to anonymous and unauthorized users through categor...

CVE-2026-53963

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, a malicious second factor name on an attacker-controlled account was not escaped in the delete confirmation dialog, allowing stored cross-site scripting when an administrator impersonated that...

CVE-2026-44787

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, the signup flow could allow newly registered users to set primarygroupid and gain whisper-group privileges without legitimate group membership on sites with whispersallowedgroups configured. This...

CVE-2026-45780

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, EventSerializer could expose invited group names, sample invitees, and attendance statistics to users who could view the topic but were not entitled to view the private event invitee list. This...

CVE-2026-45788

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, secure uploads could be exposed by pullhotlinkedimages when an attacker knew the secured upload URL and the secureuploads site setting was enabled. This issue is fixed in versions 2026.6.0,...

CVE-2026-45780

CVE-2026-45780 affects Discourse prior to versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5. The issue arises in EventSerializer, which could expose invited group names, sample invitees, and attendance statistics to users who could view the topic but were not entitled to view the private event ...

CVE-2026-45780

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, EventSerializer could expose invited group names, sample invitees, and attendance statistics to users who could view the topic but were not entitled to view the private event invitee list. This...

CVE-2026-53963

Discourse (open‑source discussion platform) has a stored XSS in the delete confirmation dialog for a malicious second factor name on an attacker‑controlled account. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, this name was not escaped, enabling XSS when an administrator impersonates that...

CVE-2026-53963

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, a malicious second factor name on an attacker-controlled account was not escaped in the delete confirmation dialog, allowing stored cross-site scripting when an administrator impersonated that...

CVE-2026-59828 Discourse: Hidden post revisions leak through adjacent visible diffs

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, post revisions that should be hidden from regular users could be leaked through visible diffs on adjacent revisions serialized by PostRevisionSerializer. This issue is fixed in versions 2026.6.0,...

CVE-2026-59828

CVE-2026-59828 affects the Discourse open‑source discussion platform. Before versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, post revisions that should be hidden from regular users could be leaked through visible diffs on adjacent revisions serialized by PostRevisionSerializer. This could di...

CVE-2026-59828

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, post revisions that should be hidden from regular users could be leaked through visible diffs on adjacent revisions serialized by PostRevisionSerializer. This issue is fixed in versions 2026.6.0,...

CVE-2026-44787 Discourse: Signup-time primary_group_id assignment grants whisperer access

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, the signup flow could allow newly registered users to set primarygroupid and gain whisper-group privileges without legitimate group membership on sites with whispersallowedgroups configured. This...