← Vulnerability feed

Vulnerability record · CVE-2026-45085 · published 12 June 2026

CVE-2026-45085: Discourse information exposure vulnerability

Discourse · Discourse

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users could create chat threads, self-deleted chat messages could be restored by their author after channel access was revoked, moderators reviewing a flagged chat message were shown the channel's current last_message (often unrelated DM content), and calendar event payloads exposed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.

5.3 CVSS 3.1 Medium EPSS 0.35% · top 73.5% CWE-200 · Information exposureCWE-862 · Missing authorization
5.3CVSS 3.1 base score
0.35%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
1References
17 Jun 2026Last modified by NVD

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, 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users could create chat threads, self-deleted chat messages could be restored by their author after channel access was revoked, moderators reviewing a flagged chat message were shown the channel's current last_message (often unrelated DM content), and calendar event payloads exposed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.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/discourse/discourse/security/advisories/GHSA-rw8j-p2gv-q33w Third Party Advisory

Track CVE-2026-45085 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.9CVE-2025-68662Discourse server-side request forgery (ssrf) vulnerabilityDiscourse is an open source discussion platform. In versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0, a hostname validation issue in Final…EPSS 0.33%9.8CVE-2023-47121Discourse server-side request forgery (ssrf) vulnerabilityDiscourse is an open source platform for community discussion. Prior to version 3.1.3 of the `stable` branch and version 3.2.0.beta3 of the `beta` an…EPSS 0.69%9.8CVE-2021-41163Discourse injection vulnerabilityDiscourse is an open source platform for community discussion. In affected versions maliciously crafted requests could lead to remote code execution.…EPSS 20%9.1CVE-2024-49765Discourse vulnerabilityDiscourse is an open source platform for community discussion. Sites that are using discourse connect but still have local logins enabled could allow…EPSS 0.36%9.0CVE-2026-53963Discourse cross-site scripting vulnerabilityDiscourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, a malicious second factor name on an attacker-c…EPSS 0.74%8.8CVE-2022-39356Discourse improper authorization vulnerabilityDiscourse is a platform for community discussion. Users who receive an invitation link that is not scoped to a single email address can enter any non…EPSS 0.61%8.8CVE-2022-21684Discourse improper authentication vulnerabilityDiscourse is an open source discussion platform. Versions prior to 2.7.13 in `stable`, 2.8.0.beta11 in `beta`, and 2.8.0.beta11 in `tests-passed` all…EPSS 0.83%8.7CVE-2026-27934Discourse vulnerabilityDiscourse is an open-source discussion platform. Versions prior to 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 have a lack of visibility checks with a …EPSS 0.42%

Source: NIST National Vulnerability Database (record CVE-2026-45085), CISA KEV, FIRST EPSS (scores of 2026-10-01). This page is refreshed as NVD updates the record.