Path Traversal in Altium Enterprise Server NIS Allows Unauthenticated Arbitrary File Write and File Read
Summary
| CVE | CVE-2026-11420 |
|---|---|
| State | PUBLISHED |
| Assigner | Altium |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-06-05 20:17:29 UTC |
| Updated | 2026-06-16 20:49:32 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 10 CRITICAL from 4760f414-e1ae-4ff1-bdad-c7a9c3538b79
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS: 0.007090000 probability, percentile 0.486500000 (date 2026-06-23)
Problem Types: CWE-22 | CWE-306 | CWE-22 CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') | CWE-306 CWE-306 Missing authentication for critical function
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | 4760f414-e1ae-4ff1-bdad-c7a9c3538b79 | Secondary | 10 | CRITICAL | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/C... |
| 4.0 | CNA | CVSS | 10 | CRITICAL | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H |
| 3.1 | [email protected] | Primary | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
CVSS v4.0 Breakdown
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Altium | On-prem Enterprise Server | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Altium | Altium Enterprise Server | affected 8.1.1 semver | Web |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.altium.com/platform/security-compliance/security-advisories | 4760f414-e1ae-4ff1-bdad-c7a9c3538b79 | www.altium.com | Vendor Advisory |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Joris Aerts, Tesla Inc. (en)