CVE-2026-72720

medium

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.

References

https://github.com/discourse/discourse/security/advisories/GHSA-3q6f-6gm9-m35v

https://github.com/discourse/discourse/pull/42247

https://github.com/discourse/discourse/pull/42246

https://github.com/discourse/discourse/pull/42245

https://github.com/discourse/discourse/pull/42244

https://github.com/discourse/discourse/commit/b25a074b165253e01fc4c8911b980fc68338ea16

https://github.com/discourse/discourse/commit/a5d3b112d598242c1d1803d5a77bf98d5fdabd75

https://github.com/discourse/discourse/commit/4b639a52f47fb3d46093bece9df147e4e9517a11

https://github.com/discourse/discourse/commit/234ee88a5b9b53bf938c53351eab20130323485f

Details

Source: Mitre, NVD

Published: 2026-08-10

Updated: 2026-08-10

Risk Information

CVSS v2

Base Score: 5.5

Vector: CVSS2#AV:N/AC:L/Au:S/C:P/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 6.4

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

Severity: Medium

EPSS

EPSS: 0.00299