# CVE-2026-45085: Discourse: Chat misauthorization and information disclosure

> Attackers can bypass chat access controls to read private messages or create threads, requiring the chat plugin to be enabled.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Jun 2026
- **Updated:** 15 Jun 2026
- **Also known as:** BIT-discourse-2026-45085, GHSA-rw8j-p2gv-q33w

## What is CVE-2026-45085?

CVE-2026-45085 is a medium-severity missing authorization vulnerability in Discourse Discourse, published on 12 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

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users could create chat threads, self-deleted chat messages could be restored by their author after channel access was revoked, moderators reviewing a flagged chat message were shown the channel's current last_message (often unrelated DM content), and calendar event payloads exposed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

Weakness: CWE-862 (Missing Authorization), CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2026-45085?

1 open source package ship an affected version, including discourse. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `discourse` | Bitnami | From 2026.1.0 | 2026.1.4, 2026.3.1, 2026.4.1 |

Products: Discourse Discourse.

## How do I fix CVE-2026-45085?

Upgrade discourse to a fixed version for your release line: 2026.1.4, 2026.3.1 or 2026.4.1.

## Is CVE-2026-45085 being exploited?

There is no known exploitation of CVE-2026-45085 in the wild and no public exploit code.

## Other vulnerabilities in Discourse Discourse

- [CVE-2021-41163](https://insights.sbomify.com/CVE-2021-41163/): RCE via malicious SNS subscription payload (critical 10.0)
- [CVE-2022-36066](https://insights.sbomify.com/CVE-2022-36066/): Discourse vulnerable to RCE via admins uploading maliciously zipped file (critical 9.1)
- [CVE-2022-39356](https://insights.sbomify.com/CVE-2022-39356/): Discourse user account takeover via email and invite link (high 8.9)
- [CVE-2023-22468](https://insights.sbomify.com/CVE-2023-22468/): Discourse vulnerable to Cross-site Scripting in local oneboxes (high 8.8)
- [CVE-2026-27934](https://insights.sbomify.com/CVE-2026-27934/): Discourse leaks private topic title and post excerpt via user action API endpoint (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-45085 and fix it if it is affected.

What it is: CVE-2026-45085 is a medium-severity missing authorization vulnerability in Discourse Discourse, published on 12 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-45085 in the wild and no public exploit code.

Affected packages and fixed versions:
- discourse (Bitnami): affected from 2026.1.0; fixed in 2026.1.4, 2026.3.1, 2026.4.1

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-45085/ (Markdown: https://insights.sbomify.com/CVE-2026-45085/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-45085
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-45085
- OSV: https://osv.dev/vulnerability/CVE-2026-45085

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-45085/
Summaries are generated and may contain mistakes; the official description above is the record.