Stored Cross‑Site Scripting in MCO
Key facts
- Attack vector
- Network
- Privileges required
- High
- User interaction
- Passive
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- None · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-79.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| MyComplianceOffice | MCO | 25.3.3.1 | — | No fix listed | CNA |
- MCO VendorMyComplianceOffice Affected 25.3.3.1 Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mycomplianceoffice:mycomplianceoffice:25.3.3.1:*:*:*:*:*:*:* | 25.3.3.1 | Vulnerable | MyComplianceOffice |
- cpe:2.3:a:mycomplianceoffice:mycomplianceoffice:25.3.3.1:*:*:*:*:*:*:* Versions 25.3.3.1 Vulnerable ·MyComplianceOffice
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-53907
- 2026-10-03 Alias added: GHSA-r38x-66p9-p239
References
More Mycomplianceoffice vulnerabilities
- TI-2026-38884 User Enumeration in MCO CVSS 4.0MEDIUM 6.9
- TI-2026-38878 Privilege Escalation in MCO CVSS 4.0HIGH 7.1
- TI-2026-38885 Arbitrary File Upload in MCO CVSS 4.0MEDIUM 5.3
- TI-2026-38882 Path Disclosure and Path Traversal in MCO CVSS 4.0MEDIUM 5.1
- TI-2026-38881 Unauthorized Access to Administrator ACL View in MCO CVSS 4.0MEDIUM 5.3
- TI-2026-38879 Insecure Direct Object Reference in MCO CVSS 4.0MEDIUM 5.3
Sources
- CVE-2026-53907 · CVE Program
- CVE-2026-53907 · NVD
- FIRST EPSS
- GHSA-r38x-66p9-p239 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences