CVE-2026-72721 (GCVE-0-2026-72721)
Vulnerability from cvelistv5
Published
2026-08-10 15:48
Modified
2026-08-10 16:59
Severity ?
5.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CWE
  • CWE-178 - Improper Handling of Case Sensitivity
Summary
Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, Onebox::DomainChecker.is_blocked? compares hostnames and SiteSetting.blocked_onebox_domains entries case-sensitively, allowing an attacker to bypass configured Onebox domain restrictions by changing character casing in a redirect target hostname. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0.
References
Impacted products
Vendor Product Version
discourse discourse Version: < 2026.1.6
Version: >= 2026.5.0-latest, < 2026.5.2
Version: >= 2026.6.0-latest, < 2026.6.1
Version: >= 2026.7.0-latest, < 2026.7.0
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