CVE-2026-72720
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.
Does this matter?
Lower severity and a low EPSS score (0.30%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 6.4 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
- EPSS
- 0.30% probability · 22th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-79
- Source
- security-advisories@github.com
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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.