Instituto Nacional de ciberseguridad. Sección Incibe
Instituto Nacional de Ciberseguridad. Sección INCIBE-CERT

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CVE-2023-53978

Severity CVSS v4.0:
MEDIUM
Type:
CWE-79 Cross-Site Scripting (XSS)
Publication date:
22/12/2025
Last modified:
22/12/2025

Description

myBB Forums 1.8.26 contains a stored cross-site scripting vulnerability in the forum announcement system that allows authenticated administrators to inject malicious scripts when creating announcements. Attackers can exploit this vulnerability by inserting script payloads in the announcement title field when adding announcements through the 'Forums and Posts' > 'Forum Announcements' interface, causing arbitrary JavaScript to execute when the announcement is displayed on the forum.

Impact

Vector 4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/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:L/VI:L/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): Low
Integrity (VI): Low
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

Base Score 3.x
6.40
Severity 3.x
MEDIUM

References to Advisories, Solutions, and Tools