CVE-2026-45775

Medium

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, a path traversal vulnerability in Discourse backup handling could allow an authenticated administrator on one site in a multisite deployment to access backup files belonging to another site when backups are stored locally. In affected configurations, an admin on Site A could potentially retrieve sensitive backup data from Site B (same host, multisite) by crafting a backup download request with a traversal payload. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0-latest.1.

SeverityMedium
CVSS6.8
Exploit probability—
ProductDiscourse
PublishedJun 12, 2026
First seenJun 12, 2026

How to fix

Update
  • discourse discourse2026.1.0, 2026.1.4, 2026.3.1, 2026.4.1 or later

Affected products

ProductAffected versionsFixed in
discourse discoursev < 2026.1.0, 2026.1.0 ≤ v < 2026.1.4, 2026.3.0 ≤ v < 2026.3.1, 2026.4.0 ≤ v < 2026.4.1, 2026.5.02026.1.0, 2026.1.4, 2026.3.1, 2026.4.1

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CVE-2026-45775 · Discourse · Dark Radar