CVE-2026-72720
Discourse: HTML injection in PrettyText.format_for_email from cooked-attribute reparsing
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.
INFO
Published Date :
Aug. 10, 2026, 4:19 p.m.
Last Modified :
Aug. 10, 2026, 4:19 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-72720
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update Discourse to version 2026.1.7 or later.
- Apply patches for 2026.6.2, 2026.7.1, or 2026.8.0-latest.1.
- Ensure proper iframe host and path validation.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-72720.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-72720 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-72720
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-72720 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-72720 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Aug. 10, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'discourse', 'product': 'discourse', 'versions': [{'status': 'affected', 'version': '< 2026.1.7'}, {'status': 'affected', 'version': '>= 2026.6.0-latest, < 2026.6.2'}, {'status': 'affected', 'version': '>= 2026.7.0-latest, < 2026.7.1'}, {'status': 'affected', 'version': '>= 2026.8.0-latest, < 2026.8.0-latest.1'}]}] 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N Added CWE CWE-79 Added Reference https://github.com/discourse/discourse/commit/234ee88a5b9b53bf938c53351eab20130323485f Added Reference https://github.com/discourse/discourse/commit/4b639a52f47fb3d46093bece9df147e4e9517a11 Added Reference https://github.com/discourse/discourse/commit/a5d3b112d598242c1d1803d5a77bf98d5fdabd75 Added Reference https://github.com/discourse/discourse/commit/b25a074b165253e01fc4c8911b980fc68338ea16 Added Reference https://github.com/discourse/discourse/pull/42244 Added Reference https://github.com/discourse/discourse/pull/42245 Added Reference https://github.com/discourse/discourse/pull/42246 Added Reference https://github.com/discourse/discourse/pull/42247 Added Reference https://github.com/discourse/discourse/security/advisories/GHSA-3q6f-6gm9-m35v