CVE-2026-72720Medium· 6.4▾ Sunlit

Discourse is an open-source discussion platform

▾ Sunlit zone — Low / medium · no exploitation signal

Depth score35/ 100 · Low

impact 35.2 · likelihood 0.1 · exploitation 0

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Proof of concept

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Published

Aug 10, 2026

Updated

Sep 8, 2026

CVSS

6.4

Vendor

—

Product

—

CWE

CWE-79

Depth score

35 · Low

EPSS

0.30% · p23

Platforms

—

Source

NVD

Vector

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

EPSS history

Exploit-prediction probability, daily snapshots since Sep 8.

0.3% → 0.3%

Timeline

Disclosure to exploitation, from the record and what we observed since indexing it.

3 events · 29 days

Aug 10, 2026Published
Disclosed via NVD
Sep 8, 2026Record revised
Last analysed / modified upstream
Sep 8, 2026EPSS first tracked
0.3%

CWE-79 #nvd

Full technical detail▾

Overview

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.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

References

Related vulnerabilities

Connected by shared product, vendor, weakness, or advisory.

#nvd

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