Vulnerability Description
Two path traversal vulnerabilities in the Network Installation Service (NIS) of Altium Enterprise Server allow an unauthenticated network attacker to write arbitrary files to any writable location on the server filesystem and to read package archive files from the server. No authentication, session, or credentials are required. Because content-controlled files can be written to web-accessible directories, or used to overwrite application binaries or configuration files, exploitation can be escalated to remote code execution in the context of the service account, and can disclose deployment package contents. Altium 365 cloud deployments are not affected, as the Network Installation Service is not part of the cloud offering.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Altium | On-Prem Enterprise Server | < 8.1.1 |
Related Weaknesses (CWE)
References
FAQ
What is CVE-2026-11420?
CVE-2026-11420 is a vulnerability with a CVSS score of 9.8 (CRITICAL). Two path traversal vulnerabilities in the Network Installation Service (NIS) of Altium Enterprise Server allow an unauthenticated network attacker to write arbitrary files to any writable location on ...
How severe is CVE-2026-11420?
CVE-2026-11420 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-11420?
Check the references section above for vendor advisories and patch information. Affected products include: Altium On-Prem Enterprise Server.