CVE-2026-72728

Discourse: Onebox iframe origin allowlist enforces URL authority boundary

MEDIUM
6.3
CVSS Score
Published: August 10, 2026 at 04:13 PM UTC
Updated: September 8, 2026 at 09:09 PM UTC
1 product affected across 1 vendorDiscourse

Using discourse by discourse?

Get instant alerts when new vulnerabilities affect discourse - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
MEDIUM6.3
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

Discourse 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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2026.1.7v < 2026.6.2v < 2026.7.1v < 2026.8.0-latest.1
Affected range stops below 2026.1.7, so it looks safe — our inference, not a vendor statement
Affected range stops below 2026.6.2, so it looks safe — our inference, not a vendor statement
Affected range stops below 2026.7.1, so it looks safe — our inference, not a vendor statement
Affected range stops below 2026.8.0-latest.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.3MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
LOW
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-20

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card