CVE-2021-37703

Discourse is an open-source platform for community discussion. In Discourse before versions 2.7.8 and 2.8.0.beta5, a user's read state for a topic such as the last read post number and the notification level is exposed.

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 max_length site setting by including html comments that are not counted toward the cha...

CVE-2022-39385

Discourse is the an open source discussion platform. In some rare cases users redeeming an invitation can be added as a participant to several private message topics that they should not be added to. They are not notified of this, it happens transparently in the background. This issue has been reso...

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-2022-39241

Discourse is a platform for community discussion. A malicious admin could use this vulnerability to perform port enumeration on the local host or other hosts on the internal network, as well as against hosts on the Internet. Latest stable, beta, and test-passed versions are now patched. As a workar...

CVE-2022-41921

Discourse is an open-source discussion platform. Prior to version 2.9.0.beta13, users can post chat messages of an unlimited length, which can cause a denial of service for other users when posting huge amounts of text. Users should upgrade to version 2.9.0.beta13, where a limit has been introduced...

CVE-2024-35227

Discourse is an open-source discussion platform. Prior to version 3.2.3 on the stable branch and version 3.3.0.beta3 on the tests-passed branch, Oneboxing against a carefully crafted malicious URL can reduce the availability of a Discourse instance. The problem has been patched in version 3.2.3 on ...

CVE-2021-37693

Discourse is an open-source platform for community discussion. In Discourse before versions 2.7.8 and 2.8.0.beta4, when adding additional email addresses to an existing account on a Discourse site an email token is generated as part of the email verification process. Deleting the additional email a...

CVE-2021-41082

Discourse is a platform for community discussion. In affected versions any private message that includes a group had its title and participating user exposed to users that do not have access to the private messages. However, access control for the private messages was not compromised as users were ...

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 duplicate ...

CVE-2023-47119

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, some links can inject arbitrary HTML tags when rendered through our Onebox engine. The issue is patched in version 3.1.3 of the s...

CVE-2025-22601

Discourse is an open source platform for community discussion. In affected versions an attacker can trick a target user to make changes to their own username via carefully crafted link using the activate-account route. This problem has been patched in the latest version of Discourse. Users are advi...

CVE-2021-39161

Discourse is an open source platform for community discussion. In affected versions category names can be used for Cross-site scripting(XSS) attacks. This is mitigated by Discourse's default Content Security Policy and this vulnerability only affects sites which have modified or disabled or changed...

CVE-2023-44388

Discourse is an open source platform for community discussion. A malicious request can cause production log files to quickly fill up and thus result in the server running out of disk space. This problem has been patched in the 3.1.1 stable and 3.2.0.beta2 versions of Discourse. It is possible to te...

CVE-2022-46150

Discourse is an open-source discussion platform. Prior to version 2.8.13 of the stable branch and version 2.9.0.beta14 of the beta and tests-passed branches, unauthorized users may learn of the existence of hidden tags and that they have been applied to topics that they have access to. This issue i...

CVE-2025-22602

Discourse is an open source platform for community discussion. In affected versions an attacker can execute arbitrary JavaScript on users' browsers by posting a malicious video placeholder html element. This issue only affects sites with CSP disabled. This problem has been patched in the latest ver...

CVE-2021-43850

Discourse is an open source platform for community discussion. In affected versions admins users can trigger a Denial of Service attack via the /message-bus/_diagnostics path. The impact of this vulnerability is greater on multisite Discourse instances (where multiple forums are served from a singl...

CVE-2023-47121

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, the embedding feature is susceptible to server side request forgery. The issue is patched in version 3.1.3 of the stable branch a...

CVE-2019-1020017

Discourse before 2.3.0 and 2.4.x before 2.4.0.beta3 lacks a confirmation screen when logging in via a user-api OTP.

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 2.9....

CVE-2025-24972

Discourse is an open-source discussion platform. Prior to versions 3.3.4 on the stable branch and 3.4.0.beta5 on the beta branch, in specific circumstances, users could be added to group direct messages despite disabling direct messaging in their preferences. Versions 3.3.4 and 3.4.0.beta5 contain ...

CVE-2021-43792

Discourse is an open source discussion platform. In affected versions a vulnerability affects users of tag groups who use the "Tags are visible only to the following groups" feature. A tag group may only allow a certain group (e.g. staff) to view certain tags. Users who were tracking or watching th...

CVE-2023-22740

Discourse is an open source platform for community discussion. Versions prior to 3.1.0.beta1 (beta) (tests-passed) are vulnerable to Allocation of Resources Without Limits. Users can create chat drafts of an unlimited length, which can cause a denial of service by generating an excessive load on th...

CVE-2024-37157

Discourse is an open-source discussion platform. Prior to version 3.2.3 on the stable branch and version 3.3.0.beta4 on the beta and tests-passed branches, a malicious actor could get the FastImage library to redirect requests to an internal Discourse IP. This issue is patched in version 3.2.3 on t...

CVE-2024-52794

Discourse is an open source platform for community discussion. Users clicking on the lightbox thumbnails could be affected. This problem is patched in the latest version of Discourse. Users are advised to upgrade. There are no known workarounds for this vulnerability.

CVE-2024-53851

Discourse is an open source platform for community discussion. In affected versions the endpoint for generating inline oneboxes for URLs wasn't enforcing limits on the number of URLs that it accepted, allowing a malicious user to inflict denial of service on some parts of the app. This vulnerabilit...

CVE-2022-39226

Discourse is an open source discussion platform. In versions prior to 2.8.9 on the stable branch and prior to 2.9.0.beta10 on the beta and tests-passed branches, a malicious actor can add large payloads of text into the Location and Website fields of a user profile, which causes issues for other us...

CVE-2022-46177

Discourse is an option source discussion platform. Prior to version 2.8.14 on the stable branch and version 3.0.0.beta16 on the beta and tests-passed branches, when a user requests for a password reset link email, then changes their primary email, the old reset email is still valid. When the old re...

CVE-2023-44391

Discourse is an open source platform for community discussion. User summaries are accessible for anonymous users even when hide_user_profiles_from_public is enabled. This problem has been patched in the 3.1.1 stable and 3.2.0.beta2 version of Discourse. Users are advised to upgrade. There are no kn...

CVE-2024-49765

Discourse is an open source platform for community discussion. Sites that are using discourse connect but still have local logins enabled could allow attackers to bypass discourse connect to create accounts and login. This problem is patched in the latest version of Discourse. Users unable to upgra...

CVE-2024-55948

Discourse is an open source platform for community discussion. In affected versions an attacker can make craft an XHR request to poison the anonymous cache (for example, the cache may have a response with missing preloaded data). This issue only affects anonymous visitors of the site. This problem ...

CVE-2021-43794

Discourse is an open source discussion platform. In affected versions an attacker can poison the cache for anonymous (i.e. not logged in) users, such that the users are shown a JSON blob instead of the HTML page. This can lead to a partial denial-of-service. This issue is patched in the latest stab...

CVE-2023-37467

Discourse is an open source discussion platform. Prior to version 3.1.0.beta7 of the beta and tests-passed branches, a CSP (Content Security Policy) nonce reuse vulnerability was discovered could allow cross-site scripting (XSS) attacks to bypass CSP protection for anonymous (i.e. unauthenticated) ...

CVE-2024-35234

Discourse is an open-source discussion platform. Prior to version 3.2.3 on the stable branch and version 3.3.0.beta3 on the tests-passed branch, an attacker can execute arbitrary JavaScript on users’ browsers by posting a specific URL containing maliciously crafted meta tags. This issue only affect...

CVE-2024-38360

Discourse is an open source platform for community discussion. In affected versions by creating replacement words with an almost unlimited number of characters, a moderator can reduce the availability of a Discourse instance. This issue has been addressed in stable version 3.2.3 and in current beta...

CVE-2024-52589

Discourse is an open source platform for community discussion. Moderators can see the Screened emails list in the admin dashboard, and through that can learn the email of a user. This problem is patched in the latest version of Discourse. Users unable to upgrade should remove moderator role from un...

CVE-2023-25172

Discourse is an open-source discussion platform. Prior to version 3.0.1 of the stable branch and version 3.1.0.beta2 of the beta and tests-passed branches, a maliciously crafted URL can be included in a user's full name field to to carry out cross-site scripting attacks on sites with a disabled or ...

CVE-2023-28112

Discourse is an open-source discussion platform. Prior to version 3.1.0.beta3 of the beta and tests-passed branches, some user provided URLs were being passed to FastImage without SSRF protection. Insufficient protections could enable attackers to trigger outbound network connections from the Disco...

CVE-2023-38684

Discourse is an open source discussion platform. Prior to version 3.0.6 of the stable branch and version 3.1.0.beta7 of the beta and tests-passed branches, in multiple controller actions, Discourse accepts limit params but does not impose any upper bound on the values being accepted. Without an upp...

CVE-2023-46130

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, some theme components allow users to add svgs with unlimited height attributes, and this can affect the availability of subsequen...

CVE-2024-23834

Discourse is an open-source discussion platform. Improperly sanitized user input could lead to an XSS vulnerability in some situations. This vulnerability only affects Discourse instances which have disabled the default Content Security Policy. The vulnerability is patched in 3.1.5 and 3.2.0.beta5....

CVE-2024-53266

Discourse is an open source platform for community discussion. In affected versions with some combinations of plugins, and with CSP disabled, activity streams in the user's profile page may be vulnerable to XSS. This has been patched in the latest version of Discourse core. Users are advised to upg...

CVE-2022-39232

Discourse is an open source discussion platform. Starting with version 2.9.0.beta5 and prior to version 2.9.0.beta10, an incomplete quote can generate a JavaScript error which will crash the current page in the browser in some cases. Version 2.9.0.beta10 added a fix and tests to ensure incomplete q...

CVE-2022-46168

Discourse is an option source discussion platform. Prior to version 2.8.14 on the stable branch and version 2.9.0.beta15 on the beta and tests-passed branches, recipients of a group SMTP email could see the email addresses of all other users inside the group SMTP topic. Most of the time this is not...

CVE-2023-22454

Discourse is an option source discussion platform. Prior to version 2.8.14 on the stable branch and version 3.0.0.beta16 on the beta and tests-passed branches, pending post titles can be used for cross-site scripting attacks. Pending posts can be created by unprivileged users when a category has th...

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 are...

CVE-2024-37299

Discourse is an open source discussion platform. Prior to 3.2.5 and 3.3.0.beta5, crafting requests to submit very long tag group names can reduce the availability of a Discourse instance. This vulnerability is fixed in 3.2.5 and 3.3.0.beta5.

CVE-2024-53994

Discourse is an open source platform for community discussion. In affected versions users who disable chat in preferences could still be reachable in some cases. This problem has been patched in the latest version of Discourse. Users are advised to upgrade. Users unable to upgrade should disable th...

CVE-2023-36466

Discourse is an open source discussion platform. When editing a topic, there is a vulnerability that enables a user to bypass the topic title validations for things like title length, number of emojis in title and blank topic titles. The issue is patched in the latest stable, beta and tests-passed ...

CVE-2024-36122

Discourse is an open-source discussion platform. Prior to version 3.2.3 on the stable branch and version 3.3.0.beta4 on the beta and tests-passed branches, moderators using the review queue to review users may see a users email address even when the Allow moderators to view email addresses setting ...