CVE-2026-33427

Severity CVSS v4.0:

LOW

Type:

Unavailable / Other

Publication date:

21/03/2026

Last modified:

24/03/2026

Description

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.

Impact

Vector 4.0

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 v4.0 Severity and Metrics:

Base Score: 2.70 LOW
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

Attack Vector (AV): Network
Attack Complexity (AC): Low
Attack Requirements (AT): None
Privileges Required (PR): None
User Interaction (UI): None
Confidentiality (VC): None
Integrity (VI): Low
Availability (VA): None
Confidentiality (SC): None
Integrity (SI): None
Availability (SA): None
Exploit Maturity (E): Unreported

Base Score 4.0

2.70

Severity 4.0

LOW

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N CVSS v3.1 Severity and Metrics:

Base Score: 7.50 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): High
Availability (A): None

Base Score 3.x

7.50

Severity 3.x

HIGH

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:a:discourse:discourse::::::::	2026.1.0 (including)	2026.1.2 (excluding)
cpe:2.3:a:discourse:discourse::::::::	2026.2.0 (including)	2026.2.1 (excluding)
cpe:2.3:a:discourse:discourse:2026.3.0::::latest:::

To consult the complete list of CPE names with products and versions, see this page

References to Advisories, Solutions, and Tools

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