CVE-2025-68479

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...

EUVD-2025-206450

Discourse is an open source discussion platform. Versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0 have a content-security-policy-mitigated cross-site scriptinv vulnerability on the Discourse Math plugin when using its KaTeX variant. This issue is patched in versions 3.5.4, 2025.11.2,...

CVE-2025-67723 Discourse vulnerable to stored Cross-site Scripting via Katex in discourse-math plugin

Discourse is an open source discussion platform. Versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0 have a content-security-policy-mitigated cross-site scriptinv vulnerability on the Discourse Math plugin when using its KaTeX variant. This issue is patched in versions 3.5.4, 2025.11.2,...

EUVD-2025-206449

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 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...

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 prior to 2025.11.2, 2025.12.1, and 2026.1....

PT-2026-5186

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. Users archives are viewable by user...

PT-2026-5194

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. Moderators can access the top uploa...

PT-2026-5182

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. Certain subscription endpoints do n...

PT-2026-5211

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. Permalinks to access-restricted...

PT-2026-5183

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, an open source discussion platform, is subject to an application-level...

CVE-2023-31142

Discourse is an open source discussion platform. Prior to version 3.0.4 of the stable branch and version 3.1.0.beta5 of the beta and tests-passed branches, if a site has modified their general category permissions, they could be set back to the default. This issue is patched in version 3.0.4 of t...

CVE-2023-25167

Discourse is an open source discussion platform. In affected versions a malicious user can cause a regular expression denial of service using a carefully crafted git URL. This issue is patched in the latest stable, beta and tests-passed versions of Discourse. Users are advised to upgrade. There a...

CVE-2023-45806

Discourse is an open source platform for community discussion. Prior to version 3.1.3 of the stable branch and version 3.2.0.beta3 of the beta and tests-passed branches, if a user has been quoted and uses a | in their full name, they might be able to trigger a bug that generates a lot of duplicat...

CVE-2022-23549

Discourse is an option source discussion platform. Prior to version 2.8.14 on the stable branch and version 2.9.0.beta16 on the beta and tests-passed branches, users can create posts with raw body longer than the maxlength site setting by including html comments that are not counted toward the...

CVE-2022-23548

Discourse is an option source discussion platform. Prior to version 2.8.14 on the stable branch and version 2.9.0.beta16 on the beta and tests-passed branches, parsing posts can be susceptible to regular expression denial of service ReDoS attacks. This issue is patched in versions 2.8.14 and...

CVE-2023-43659

Discourse is an open source platform for community discussion. Improper escaping of user input allowed for Cross-site Scripting attacks via the digest email preview UI. This issue only affects sites with CSP disabled. This issue has been patched in the 3.1.1 stable release as well as the...

CVE-2021-41163

Discourse is an open source platform for community discussion. In affected versions maliciously crafted requests could lead to remote code execution. This resulted from a lack of validation in subscribeurl values. This issue is patched in the latest stable, beta and tests-passed versions of...

CVE-2025-23023

Discourse is an open source platform for community discussion. In affected versions an attacker can carefully craft a request with the right request headers to poison the anonymous cache for example, the cache may have a response with missing preloaded data. This issue only affects anonymous...

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...