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CVE-2026-72720

Discourse: HTML injection in PrettyText.format_for_email from cooked-attribute reparsing

Published: Aug 10, 2026Updated: Aug 10, 2026 Sources: CVE List NVDCWE-79
6.4MEDIUM
NVD MITRE
EPSS Score
0.3%
Top 78.1%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available
Self-Check
OpenVAS

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:LUI:NS:CC:LI:LA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:LPrivileges Required
Low
UI:NUser Interaction
None
Scope
S:CScope
Changed
Impact
C:LConfidentiality
Low
I:LIntegrity
Low
A:NAvailability
None
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Weaknesses

CWE-79

Affected Products

discourse
commercial·USaka discourse.org
discourse
Web & CMS Plugins

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques
Execution
Initial Access
View detailed technique mapping

References

https://github.com/discourse/discourse/security/advisories/GHSA-3q6f-6gm9-m35v
github.com
https://github.com/discourse/discourse/pull/42244
github.com
https://github.com/discourse/discourse/pull/42245
github.com
and 6 more references View all →

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