CVEvulnerability
CVE-2026-72721
5.3 MEDIUM
Official page ↗
- Status
- Deferred
- Published
- 2026-08-10
- Last modified
- 2026-09-08
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 5.3 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- Weaknesses
- CWE-178
Description
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.
Related
Weakness · CWE (1)
- CWE-178 Improper Handling of Case Sensitivity weakness
References
- https://github.com/discourse/discourse/commit/a3e10759fef47f03d450649bb51d9e84f4c68b8f github.com
- https://github.com/discourse/discourse/commit/c2eb6b0e5597d6f28f4be739b83300bc9c69e3cd github.com
- https://github.com/discourse/discourse/commit/caa615c371b1696982ee11ac8f3558f0f8ced584 github.com
- https://github.com/discourse/discourse/commit/f503971d311b7b0dfdb751ee8cfd67e8cb99f5c5 github.com
- https://github.com/discourse/discourse/pull/42091 github.com
- https://github.com/discourse/discourse/pull/42092 github.com
- https://github.com/discourse/discourse/pull/42093 github.com
- https://github.com/discourse/discourse/pull/42094 github.com
- https://github.com/discourse/discourse/security/advisories/GHSA-3x7x-24rq-h5j6 github.com