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.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Changed

Confidentiality Impact Low

Integrity Impact Low

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00299.

Exploitation none

Automatable no

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
discourse discourse affected
Version Status Constraints
< 2026.1.7 affected —
>= 2026.6.0-latest, < 2026.6.2 affected —
>= 2026.7.0-latest, < 2026.7.1 affected —
>= 2026.8.0-latest, < 2026.8.0-latest.1 affected —

No data.

No data.

OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.

Vendors Products
Discourse Subscribe
Discourse Subscribe

Project Subscriptions

Vendors Products
Discourse Subscribe
Discourse Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/discourse/discourse/commit/234ee88a5b9b53bf938c53351eab20130323485f cve-icon cve-icon
https://github.com/discourse/discourse/commit/4b639a52f47fb3d46093bece9df147e4e9517a11 cve-icon cve-icon
https://github.com/discourse/discourse/commit/a5d3b112d598242c1d1803d5a77bf98d5fdabd75 cve-icon cve-icon
https://github.com/discourse/discourse/commit/b25a074b165253e01fc4c8911b980fc68338ea16 cve-icon cve-icon
https://github.com/discourse/discourse/pull/42244 cve-icon cve-icon
https://github.com/discourse/discourse/pull/42245 cve-icon cve-icon
https://github.com/discourse/discourse/pull/42246 cve-icon cve-icon
https://github.com/discourse/discourse/pull/42247 cve-icon cve-icon
https://github.com/discourse/discourse/security/advisories/GHSA-3q6f-6gm9-m35v cve-icon cve-icon
History

Tue, 11 Aug 2026 04:15:00 +0000

Type Values Removed Values Added
First Time appeared Discourse
Discourse discourse
Vendors & Products Discourse
Discourse discourse

Mon, 10 Aug 2026 19:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Mon, 10 Aug 2026 16:15:00 +0000

Type Values Removed Values Added
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.
Title Discourse: HTML injection in PrettyText.format_for_email from cooked-attribute reparsing
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 6.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-10T18:17:21.640Z

Reserved: 2026-08-10T13:48:09.545Z

Link: CVE-2026-72720

cve-icon Vulnrichment

Updated: 2026-08-10T18:13:44.882Z

cve-icon NVD

Status : Received

Published: 2026-08-10T16:19:49.197

Modified: 2026-08-10T19:17:33.550

Link: CVE-2026-72720

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-11T04:00:07Z

Weaknesses