CVE-2026-91157

Discourse: Media uploads remain publicly accessible after category permissions are restricted

State
Published
Severity
7.5 High
Published
Oct 14, 2026
Updated
Oct 20, 2026
Reserved
Sep 14, 2026

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
3.17.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:NGitHub_M

Weaknesses

  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
  • CWE-863 Incorrect Authorization

Affected Products

ProductVersions
discoursediscourse
  • < 2026.1.9Affected
  • >= 2026.7.0-latest, < 2026.7.3Affected
  • >= 2026.8.0-latest, < 2026.8.1Affected
  • >= 2026.9.0-latest, < 2026.9.0Affected

References

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