# CVE-2026-23743: Discourse allows permalinks to restricted resources to leak resource slugs to unauthorized users

> Unauthorized users can leak sensitive resource slugs from private topics via permalinks, exposing private titles in redirect headers and error pages.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 28 Jan 2026
- **Updated:** 28 Jan 2026
- **Also known as:** BIT-discourse-2026-23743, GHSA-v5jw-rxc6-4cvv

## What is CVE-2026-23743?

CVE-2026-23743 is a medium-severity vulnerability in Discourse Discourse, published on 28 Jan 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. In versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0, permalinks pointing to access-restricted resources (private topics, categories, posts, or hidden tags) were redirecting users to URLs containing the resource slug, even when the user didn't have access to view the resource. This leaked potentially sensitive information (e.g., private topic titles) via the redirect Location header and the 404 page's search box. This issue is patched in versions 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0. No known workarounds are available.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2026-23743?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `discourse` | Bitnami | All versions | 3.5.4, 2025.11.2, 2026.2.0 |

Products: Discourse Discourse.

## How do I fix CVE-2026-23743?

Upgrade discourse to a fixed version for your release line: 3.5.4, 2025.11.2 or 2026.2.0.

## Is CVE-2026-23743 being exploited?

There is no known exploitation of CVE-2026-23743 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-2026-23743 and fix it if it is affected.

What it is: CVE-2026-23743 is a medium-severity vulnerability in Discourse Discourse, published on 28 Jan 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-2026-23743 in the wild and no public exploit code.

Affected packages and fixed versions:
- discourse (Bitnami): affected all versions; fixed in 3.5.4, 2025.11.2, 2026.2.0

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-2026-23743/ (Markdown: https://insights.sbomify.com/CVE-2026-23743/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23743
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23743
- OSV: https://osv.dev/vulnerability/CVE-2026-23743

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23743/
Summaries are generated and may contain mistakes; the official description above is the record.