CVE-2026-72720
Discourse: HTML injection in PrettyText.format_for_email from cooked-attribute reparsing
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
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.
Timeline
ID reserved
By GitHub_M
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium6.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N |
| NVDNVD · Deferred | 3.1 | Medium6.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.41% · top 65% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.4.
Weakness
Affected products
References (9)
- https://github.com/discourse/discourse/security/advisories/GHSA-3q6f-6gm9-m35v (opens in a new tab)x_refsource_CONFIRM
- https://github.com/discourse/discourse/pull/42244 (opens in a new tab)x_refsource_MISC
- https://github.com/discourse/discourse/pull/42245 (opens in a new tab)x_refsource_MISC
- https://github.com/discourse/discourse/pull/42246 (opens in a new tab)x_refsource_MISC
- https://github.com/discourse/discourse/pull/42247 (opens in a new tab)x_refsource_MISC
- https://github.com/discourse/discourse/commit/234ee88a5b9b53bf938c53351eab20130323485f (opens in a new tab)x_refsource_MISC
- https://github.com/discourse/discourse/commit/4b639a52f47fb3d46093bece9df147e4e9517a11 (opens in a new tab)x_refsource_MISC
- https://github.com/discourse/discourse/commit/a5d3b112d598242c1d1803d5a77bf98d5fdabd75 (opens in a new tab)x_refsource_MISC
- https://github.com/discourse/discourse/commit/b25a074b165253e01fc4c8911b980fc68338ea16 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-72720)Record last updated .