CVE-2026-33427 PUBLISHED

Discourse Authorization Page Displays Unvalidated Redirect Domain

Assigner: GitHub_M
Reserved: 19.03.2026 Published: 20.03.2026 Updated: 20.03.2026

Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, an unauthenticated attacker can cause a legitimate Discourse authorization page to display an attacker-controlled domain, facilitating social engineering attacks against users. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. No known workarounds are available.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U
CVSS Score: 2.7

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	Low	Integrity	None
Attack Requirements	None	Availability	None	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

Product Status

Vendor	discourse
Product	discourse
Versions	Version >= 2026.1.0-latest, < 2026.1.2 is affected Version >= 2026.2.0-latest, < 2026.2.1 is affected Version = 2026.3.0-latest is affected

References

https://github.com/discourse/discourse/security/advisories/GHSA-9vhg-2mx3-mqfr

Problem Types

CWE-862: Missing Authorization CWE