5.3 MEDIUM
- CVSS version (CVSS): 3.1
- Attack Vector (AV): Network (N)
- Attack Complexity (AC): Low (L)
- Privileges Required (PR): None (N)
- User Interaction (UI): None (N)
- Scope (S): Unchanged (U)
- Confidentiality (C): Low (L)
- Integrity (I): None (N)
- Availability (A): None (N)
- Modified Attack Vector (MAV): Network (N)
- Modified Attack Complexity (MAC): Low (L)
- Modified Privileges Required (MPR): None (N)
- Modified User Interaction (MUI): None (N)
- Modified Confidentiality (MC): Low (L)
- Modified Scope (MS): Unchanged (U)
- Modified Integrity (MI): None (N)
- Modified Availability (MA): None (N)
Activity log
- Created suggestion
Discourse: Onebox Domain Blocklist Bypass via Case-Sensitive Comparison
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
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https://github.com/discourse/discourse/security/advisories/GHSA-3x7x-24rq-h5j6 x_refsource_CONFIRM
-
https://github.com/discourse/discourse/pull/42091 x_refsource_MISC
-
https://github.com/discourse/discourse/pull/42092 x_refsource_MISC
-
https://github.com/discourse/discourse/pull/42093 x_refsource_MISC
-
https://github.com/discourse/discourse/pull/42094 x_refsource_MISC
Affected products
- ==>= 2026.6.0-latest, < 2026.6.1
- ==>= 2026.5.0-latest, < 2026.5.2
- ==< 2026.1.6
- ==>= 2026.7.0-latest, < 2026.7.0
Matching in nixpkgs
pkgs.discourse
Open source discussion platform
pkgs.discourseAllPlugins
Open source discussion platform
pkgs.discourse-mail-receiver
Helper program which receives incoming mail for Discourse
pkgs.python313Packages.pydiscourse
Python library for working with Discourse
pkgs.python314Packages.pydiscourse
Python library for working with Discourse
pkgs.grafanaPlugins.grafana-discourse-datasource
Allows users to search and view topics, posts, users, tags, categories, and reports on a given Discourse forum through Grafana
Package maintainers
-
@leona-ya Leona Maroni <nix@leona.is>
-
@talyz Kim Lindberger <kim.lindberger@gmail.com>
-
@nagisa Simonas Kazlauskas <nixpkgs@kazlauskas.me>
-
@Dettorer Paul Hervot <paul.hervot@dettorer.net>