CVE-2026-53907 PUBLISHED

Stored Cross‑Site Scripting in MCO

Assigner: CERT-PL
Reserved: 11.06.2026 Published: 01.07.2026 Updated: 01.07.2026

MCO is vulnerable to Stored Cross‑Site Scripting (XSS) via the application logo upload functionality. An attacker with the ability to change the application logo can upload a crafted SVG file containing malicious JavaScript code that is executed when the logo is rendered or opened.

Because vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 25.3.3.1 but may also affect other versions.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N
CVSS Score: 4.8

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

CVSS 4.0

Product Status

Vendor	MyComplianceOffice
Product	MCO
Versions	Default: unknown Version 25.3.3.1 is affected

Credits

Hubert Decyusz (AFINE Team) finder

References

Problem Types

CWE-79 Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') CWE

Impacts

CAPEC-63 Cross-Site Scripting (XSS)