CVE-2026-72720
Description
Discourse is an open-source discussion platform. Prior to 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0-latest.1, Discourse has HTML injection in PrettyText.format_for_email because cooked attribute values are reparsed as markup. Crafted Vimeo iframe sources, secure-upload URLs or dimensions, and hashtag data-slug values can cause decoded attribute text to be reinterpreted as HTML. The vulnerable conversion also fails to strictly validate the Vimeo iframe host and path, allowing non-Vimeo allowlisted iframes to be converted. This issue is fixed in versions 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0-latest.1.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
References
- https://github.com/discourse/discourse/commit/234ee88a5b9b53bf938c53351eab20130323485f
- https://github.com/discourse/discourse/commit/4b639a52f47fb3d46093bece9df147e4e9517a11
- https://github.com/discourse/discourse/commit/a5d3b112d598242c1d1803d5a77bf98d5fdabd75
- https://github.com/discourse/discourse/commit/b25a074b165253e01fc4c8911b980fc68338ea16
- https://github.com/discourse/discourse/pull/42244
- https://github.com/discourse/discourse/pull/42245
- https://github.com/discourse/discourse/pull/42246
- https://github.com/discourse/discourse/pull/42247
- https://github.com/discourse/discourse/security/advisories/GHSA-3q6f-6gm9-m35v
CWEs
CWE-79
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.