CVE-2026-21865

Discourse is an open source discussion platform. In versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0, moderators can convert some personal messages to public topics when they shouldn't have access. This issue is patched in versions 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0. As a...

CVE-2025-69289 Discourse has insecure default configuration that allows non-admin moderators to takeover any non-staff account via email change

Discourse is an open source discussion platform. A privilege escalation vulnerability in versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0 allows a non-admin moderator to bypass email-change restrictions, allowing a takeover of non-staff accounts. This issue is patched in versions 3.5.4...

CVE-2025-66488

Discourse is an open source discussion platform. A vulnerability present in versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0 affects anyone who uses S3 for uploads. While scripts may be executed, they will only be run in the context of the S3/CDN domain, with no site credentials...

EUVD-2025-206425

Discourse is an open source discussion platform. Versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0 have an application level denial of service vulnerabilityin the username change functionality at try.discourse.org. The vulnerability allows attackers to cause noticeable server delays and...

EUVD-2025-206451

Discourse is an open source discussion platform. In versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0, some subscription endpoints lack proper checking for ownership before making changes. This issue is patched in versions 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0. No known workarounds...

CVE-2025-66488 Discourse allows script execution in uploaded HTML/XML files on S3

Discourse is an open source discussion platform. A vulnerability present in versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0 affects anyone who uses S3 for uploads. While scripts may be executed, they will only be run in the context of the S3/CDN domain, with no site credentials...

CVE-2025-66488

Discourse (open source platform) has a vulnerability affecting installations using S3 for uploads, present in versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0. The issue allows script execution within the S3/CDN domain context when HTML/XML uploads are processed; no site credentials ar...

Discourse security vulnerabilities

Discourse is an open-source community discussion platform developed by Discourse. This platform includes features such as communities, email communication, and chat rooms. Vulnerabilities exist in versions of Discourse prior to 3.5.4, as well as versions before 2025.11.2, 2025.12.1, and 2026.1.0...

PT-2026-5184

Name of the Vulnerable Software and Affected Versions Discourse versions prior to 3.5.4 Discourse versions prior to 2025.11.2 Discourse versions prior to 2025.12.1 Discourse versions prior to 2026.1.0 Description Discourse is an open source discussion platform. An endpoint allows any authenticate...

Discourse security vulnerabilities

Discourse is an open-source community discussion platform developed by Discourse. This platform includes features such as communities, email communication, and chat rooms. Vulnerabilities exist in versions of Discourse prior to 3.5.4, as well as versions before 2025.11.2, 2025.12.1, and 2026.1.0...

CVE-2023-49099

Discourse is a platform for community discussion. Under very specific circumstances, secure upload URLs associated with posts can be accessed by guest users even when login is required. This vulnerability has been patched in 3.2.0.beta4 and 3.1.4...

CVE-2020-24327

Server Side Request Forgery SSRF vulnerability exists in Discourse 2.3.2 and 2.6 via the email function. When writing an email in an editor, you can upload pictures of remote websites...

CVE-2023-29196

Discourse is an open source platform for community discussion. This vulnerability is not exploitable on the default install of Discourse. A custom feature must be enabled for it to work at all, and the attacker’s payload must pass the CSP to be executed. However, if an attacker succeeds in...

CVE-2023-45147

Discourse is an open source community platform. In affected versions any user can create a topic and add arbitrary custom fields to a topic. The severity of this vulnerability depends on what plugins are installed and how the plugins uses topic custom fields. For a default Discourse installation...

CVE-2022-23641

Discourse is an open source discussion platform. In versions prior to 2.8.1 in the stable branch, 2.9.0.beta2 in the beta branch, and 2.9.0.beta2 in the tests-passed branch, users can trigger a Denial of Service attack by posting a streaming URL. Parsing Oneboxes in the background job trigger an...

CVE-2022-23546

In version 2.9.0.beta14 of Discourse, an open-source discussion platform, maliciously embedded urls can leak an admin's digest of recent topics, possibly exposing private information. A patch is available for version 2.9.0.beta15. There are no known workarounds for this issue...

CVE-2022-31182

Discourse is the an open source discussion platform. In affected versions a maliciously crafted request for static assets could cause error responses to be cached by Discourse's default NGINX proxy configuration. A corrected NGINX configuration is included in the latest stable, beta and...

CVE-2022-31096

Discourse is an open source discussion platform. Under certain conditions, a logged in user can redeem an invite with an email that either doesn't match the invite's email or does not adhere to the email domain restriction of an invite link. The impact of this flaw is aggravated when the invite h...

CVE-2023-45131

Discourse is an open source platform for community discussion. New chat messages can be read by making an unauthenticated POST request to MessageBus. This issue is patched in the 3.1.1 stable and 3.2.0.beta2 versions of Discourse. Users are advised to upgrade. There are no known workarounds for...

CVE-2025-64528 Users are able to find users by name even when `enable_names` is off

Discourse is an open source discussion platform. Prior to versions 3.5.3, 2025.11.1, and 2025.12.0, an attacker who knows part of a username can find the user and their full name via UI or API, even when enablenames is disabled. Versions 3.5.3, 2025.11.1, and 2025.12.0 contain a fix...