CVE-2026-91157
Deferred
Deferred - Pending Action
Information Disclosure in Discourse Prior to 2026.9.0
Vulnerability report for CVE-2026-91157, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-14
Last updated on: 2026-10-14
Assigner: GitHub, Inc.
Description
Description
Discourse is an open-source discussion platform. Prior to 2026.9.0, 2026.8.1, 2026.7.3, and 2026.1.9, sites with secure uploads enabled did not reconcile existing upload security metadata when a previously public category became read-restricted or when category permissions changed during a bulk import. Media and attachments uploaded while the category was public retained a public accessibility flag and remained reachable by anonymous users through their short upload URLs, including uploads associated with deleted topics. This issue is fixed in versions 2026.9.0, 2026.8.1, 2026.7.3, and 2026.1.9.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| discourse | discourse | < 2026.1.9 |
| discourse | discourse | >= 2026.7.0-latest, < 2026.7.3 |
| discourse | discourse | >= 2026.8.0-latest, < 2026.8.1 |
| discourse | discourse | >= 2026.9.0-latest, < 2026.9.0 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-863 | The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. |
| CWE-200 | The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. |
