CVE-2026-72720

MEDIUMCVSS 6.4/10

Last modified

CVE-2026-72720 is a medium-severity vulnerability rated 6.4/10 on the CVSS scale. 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.

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.

Metrics

CVSS 3.1
6.4/10

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

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
discoursediscourse< 2026.1.7; >= 2026.6.0-latest, < 2026.6.2; >= 2026.7.0-latest, < 2026.7.1; >= 2026.8.0-latest, < 2026.8.0-latest.1

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is CVE-2026-72720?
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.
How severe is CVE-2026-72720?
CVE-2026-72720 has a CVSS score of 6.4/10 (MEDIUM severity).
How do I fix CVE-2026-72720?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST