Discourse: Onebox iframe origin allowlist enforces URL authority boundary

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-72728
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-10 17:17:37 UTC
Updated2026-08-10 21:17:24 UTC
DescriptionDiscourse is an open-source discussion platform. Prior to 2026.1.7, an authenticated user could submit specially formed URLs that bypassed the Onebox allowlist and embedded malicious content in a site. This issue is fixed in versions 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0-latest.1.

Risk And Classification

Primary CVSS: v3.1 6.3 MEDIUM from [email protected]

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

Problem Types: CWE-20 | CWE-20 CWE-20: Improper Input Validation

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary6.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
3.1CNADECLARED6.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Discourse Discourse affected < 2026.1.7 Not specified
CNA Discourse Discourse affected >= 2026.6.0-latest, < 2026.6.2 Not specified
CNA Discourse Discourse affected >= 2026.7.0-latest, < 2026.7.1 Not specified
CNA Discourse Discourse affected >= 2026.8.0-latest, < 2026.8.0-latest.1 Not specified

References

ReferenceSourceLinkTags
github.com/discourse/discourse/commit/92eec47e8b477cb8b4ccdb237e26dc1ba8... [email protected] github.com
github.com/discourse/discourse/security/advisories/GHSA-qp9j-3v7r-wrvr [email protected] github.com
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NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

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