CVE-2026-44782 Discourse: GroupPostSerializer leaks hidden full names through reaction post association

What is CVE-2026-44782?

CVE-2026-44782 is a medium-severity vulnerability in Discourse Discourse, published on 12 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.4, 2026.3.0-latest to before 2026.3.1, and 2026.4.0-latest to before 2026.4.1, GroupPostSerializer declared include_user_long_name? as the predicate for its :name attribute, but AMS looks for include_name?. The misnamed predicate was never called, so object.user.name was always serialized regardless of SiteSetting.enable_names. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0-latest.1.

Weakness: CWE-200

Which versions are affected by CVE-2026-44782?

1 open source package ship an affected version, including discourse. It affects 1 product.

Products include Discourse Discourse.

How do I fix CVE-2026-44782?

Upgrade discourse to a fixed version for your release line: 2026.1.4, 2026.3.1 or 2026.4.1.

Is CVE-2026-44782 being exploited?

There is no known exploitation of CVE-2026-44782 in the wild and no public exploit code.

Other vulnerabilities in Discourse Discourse

• CVE-2021-41163 RCE via malicious SNS subscription payload Critical 10.0
• CVE-2022-36066 Discourse vulnerable to RCE via admins uploading maliciously zipped file Critical 9.1
• CVE-2022-39356 Discourse user account takeover via email and invite link High 8.9
• CVE-2023-22468 Discourse vulnerable to Cross-site Scripting in local oneboxes High 8.8
• CVE-2026-27934 Discourse leaks private topic title and post excerpt via user action API endpoint High 8.7

All Discourse Discourse vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BIT-discourse-2026-44782, GHSA-h3mq-9r6w-h33j.