CVE-2026-35054

Severity CVSS v4.0:

MEDIUM

Type:

CWE-79 Cross-Site Scripting (XSS)

Publication date:

01/04/2026

Last modified:

01/04/2026

Description

XenForo before 2.3.9 is vulnerable to stored cross-site scripting (XSS) related to BB code rendering. An attacker can inject malicious scripts through BB code that are stored and executed when other users view the content.

Impact

Vector 4.0

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N CVSS v4.0 Severity and Metrics:

Base Score: 5.10 MEDIUM
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

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

Base Score 4.0

5.10

Severity 4.0

MEDIUM

Vector 3.x

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

Base Score: 6.40 MEDIUM
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

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