CVE-2026-53963

Severity CVSS v4.0:

Pending analysis

Type:

CWE-79 Cross-Site Scripting (XSS)

Publication date:

09/07/2026

Last modified:

14/07/2026

Description

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, a malicious second factor name on an attacker-controlled account was not escaped in the delete confirmation dialog, allowing stored cross-site scripting when an administrator impersonated that account. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.

Impact

Vector 3.x

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

Base Score: 7.30 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N

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

Base Score 3.x

7.30

Severity 3.x

HIGH

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:a:discourse:discourse::::::::	2026.1.0 (including)	2026.1.5 (excluding)
cpe:2.3:a:discourse:discourse::::::::	2026.4.0 (including)	2026.4.2 (excluding)
cpe:2.3:a:discourse:discourse::::::::	2026.5.0 (including)	2026.5.1 (excluding)
cpe:2.3:a:discourse:discourse:2026.6.0::::latest:::

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

CVE-2026-53963

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools