What is CVE-2026-11420?

CVE-2026-11420 is a critical-severity vulnerability in Altium Enterprise Server, classified under Path Traversal. CVSS score: 9.8/10. Published 2026-06-05.

How severe is CVE-2026-11420?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Auth bypass in Altium Enterprise Server

CVE-2026-11420

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 packa…

Vulnerability class: Path Traversal (Directory Traversal)

EPSS: 0.007 (49.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Altium Enterprise Server — versions 0
Altium On-prem_enterprise_server

Weakness classification (CWE)

References

4760f414-e1ae-4ff1-bdad-c7a9c3538b79 (Vendor Advisory)

Frequently asked questions

What is CVE-2026-11420?: CVE-2026-11420 is a critical-severity vulnerability in Altium Enterprise Server, classified under Path Traversal. CVSS score: 9.8/10. Published 2026-06-05.
How severe is CVE-2026-11420?: Critical severity. CVSS v3 base score is 9.8 out of 10.