Transmission of Private Resources into a New Sphere ('Resource Leak') in Discourse - CVE-2021-32788
Published: July 27, 2021 / Updated: July 1, 2026
Vulnerability identifier: #VU136571
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2021-32788
CWE-ID: CWE-402
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Civilized Discourse Construction Kit, Inc.
Affected software:
Discourse
Discourse
Detailed vulnerability description
The vulnerability allows a remote user to disclose sensitive information.
The vulnerability exists due to transmission of private resources into a new sphere in whisper post handling when processing personal messages and post stream state changes. A remote user can participate in a personal message or observe topic metadata after deletion of the last post to disclose sensitive information.
Non-staff participants can learn the creator of a whisper post even though the whisper content itself is not visible to them.
How to mitigate CVE-2021-32788
Install security update from vendor's website.