CVE-2026-45775 — Discourse: Cross-site backup access via path traversal in multisite local backups

Description (CNA)

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.

Affected (CNA)

Vendor / product	Versions
discourse / discourse	affected >= 2026.1.0-latest, < 2026.1.4; affected >= 2026.3.0-latest, < 2026.3.1; affected >= 2026.4.0-latest, < 2026.4.1

CWE

CWE-22

References

https://github.com/discourse/discourse/security/advisories/GHSA-5j6v-4x6g-9pg5

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.