ShellCodeX
Tools • Events • News • Insights
ShellCodeX vulnerability brief
MEDIUM Received

CVE-2026-72721

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, Onebox::DomainChecker.is_blocked? compares hostnames and SiteSetting.blocked_onebox_domains entries case-sensitively, allowing an attacker to bypass configured Onebox domain restrictions by changing character casing in a redirect target hostname. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0.

Published 10 Aug 2026, 16:19 UTC Last modified 10 Aug 2026, 17:17 UTC
01

Attack profile

The conditions required to exploit this vulnerability and its potential impact.

Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Unchanged
Confidentiality Low
Integrity None
Availability None
Exploitability3.9
Impact1.4
02

Affected products

Product applicability statements supplied with the NVD record.

NVD has not published structured affected-product data for this record.
03

Weakness classification

CWE categories help security teams group the underlying software weakness.

CWECWE-178
04

Source references

External advisories, patches and technical reports attached to this CVE record.

NVD National Vulnerability Database recordnvd.nist.gov 01 Technical reference security-advisories@github.com 02 Technical reference security-advisories@github.com 03 Technical reference security-advisories@github.com 04 Technical reference security-advisories@github.com 05 Technical reference security-advisories@github.com 06 Technical reference security-advisories@github.com 07 Technical reference security-advisories@github.com 08 Technical reference security-advisories@github.com 09 Technical reference security-advisories@github.com