Vulnerability Report

CVE-2026-45085

Title: Multiple Authorization and Disclosure Issues in Discourse Chat Plugin

Information Disclosure

Proof Of Concept

No public PoC currently indexed for CVE-2026-45085.

CWE Category CWE-200

Published Date Jun 12, 2026

Modified Date Jun 17, 2026

Exploit Status Not Found

Score 5.3 CVSS v3.1

Exploit Probability (EPSS)

0.21%

Vulnerability Summary

CVE-2026-45085: 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, four authorization/disclosure issues in the chat plugin (one also involving discourse-calendar): read-only category users could create chat threads, self-deleted chat messages could be restored by their author after channel access was revoked, moderators reviewing a flagged chat message were shown the channel's current last_message (often unrelated DM content), and calendar event payloads exposed the attached chat channel and its last message to viewers without chat access (including anonymous users). This affects sites with the chat plugin enabled; the calendar issue additionally requires discourse-calendar. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0-latest.1.

Impacted Vendors

discourse 1

Reference Links

https://github.com/discourse/discourse/security/advisories/GHSA-rw8j-p2gv-q33w

CVSS v3.1

Source Entity [email protected]

Severity MEDIUM

5.3

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

NONE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

UNCHANGED

RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-45085 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

June 17, 2026 MODIFIED

Vulnerability data updated via NVD.

June 15, 2026 MODIFIED

Vulnerability data updated via NVD.

June 12, 2026 MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector NETWORK

Complexity LOW

Privileges N/A

Interaction NONE

CVSS Vector String


                                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Affected Stack

No specific products linked.