Information disclosure in Discourse - CVE-2021-37703
Published: August 13, 2021 / Updated: July 1, 2026
Vulnerability identifier: #VU136568
CSH Severity: Low
CVSS v4: 4.6 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2021-37703
CWE-ID: CWE-200
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to exposure of sensitive information in the unread state message handling when processing server-published unread state messages. A remote attacker can trigger a victim client to receive a message that exposes a user's read state to disclose sensitive information.
User interaction is required.
Affected software
Discourse
How to mitigate CVE-2021-37703
Install security update from vendor's website.
Discourse - addressed in versions 2.7.8, 2.8.0 beta5