Is CVE-2026-31869 actively exploited?

No active exploitation of CVE-2026-31869 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-31869 be exploited remotely?

Yes. CVE-2026-31869 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-31869?

CVE-2026-31869 has a CVSS score of 4.3 (MEDIUM).

HOME VULNERABILITIESCVE-2026-31869

MEDIUM

CVE-2026-31869

CWE-200Published: March 20, 2026· Updated: Mar 24, 2026

4.3

CVSS v3.1

EPSS:0.04%probability of exploitation in 30 daysPercentile:11.5th

Official Description

Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, the ComposerController#mentions endpoint reveals hidden group membership to any authenticated user who can message the group. By supplying allowed_names referencing a hidden-membership group and probing arbitrary usernames, an attacker can infer membership based on whether user_reasons returns "private" for a given user. This bypasses group member-visibility controls. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. To work around this issue, restrict the messageable policy of any hidden-membership group to staff or group members only, so untrusted users cannot reach the vulnerable code path.

NVD Source

Technical Analysis

CVE-2026-31869 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

From a weakness classification perspective (CWE-200): Information exposure vulnerabilities leak sensitive data to unauthorized actors.