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TI-2026-09855 Aliases CVE-2026-11420GHSA-q58x-mgvc-jhw9

Path Traversal in Altium Enterprise Server NIS Allows Unauthenticated Arbitrary File Write and File Read

Priority MEDIUM 50CWE-22Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-306.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00709 53rd percentileScored 2026-11-07
Fix Fixed Altium Enterprise Server (Altium): 8.1.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
AltiumAltium Enterprise Serverbefore 8.1.18.1.1Patch availableCNA
  • Altium Enterprise Server VendorAltium Affected before 8.1.1 Fixed in 8.1.1 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:altium:on-prem_enterprise_server:*:*:*:*:*:*:*:*before 8.1.1VulnerableAltium
  • cpe:2.3:a:altium:on-prem_enterprise_server:*:*:*:*:*:*:*:* Versions before 8.1.1 Vulnerable ·Altium

Remediation

  • Fix · CNA Altium Enterprise Server (Altium) Fixed in 8.1.1

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    Altium Enterprise Server 8.1.1

    7 records Highest priority Priority MEDIUM 6 MEDIUM, 1 LOW

    Other records, highest priority first

    • TI-2026-09862 Path Traversal in Altium Vault ScriptsController Allows Unauthenticated Remote Code ExecutionPriority MEDIUM 51
    • TI-2026-09854 Path Traversal in Altium Enterprise Server Vault UploadController Allows Arbitrary File WritePriority MEDIUM 49
    • TI-2026-09851 Path traversal in Altium Enterprise ServerPriority MEDIUM 49
    Show all 7 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-11420
  2. 2026-10-03 Alias added: GHSA-q58x-mgvc-jhw9

References

Advisory 1

  • TI-2026-09854 Path Traversal in Altium Enterprise Server Vault UploadController Allows Arbitrary File Write CVSS 4.0CRITICAL 9.4
  • TI-2026-09851 Path traversal in Altium Enterprise Server CVSS 4.0CRITICAL 10.0
  • TI-2025-20220 SQL Injection in AES Due to Inactive SQL Parsing Configuration CVSS 3.1CRITICAL 9.8
  • TI-2026-00763 Stored Cross-Site Scripting in Altium Enterprise Server Workflow Engine Allows Privilege Escalation CVSS 3.1HIGH 8.0
  • TI-2025-20222 HTML Injection Leading to Script Execution in Altium Enterprise Server CVSS 3.1HIGH 7.6
  • TI-2025-20221 Stored Cross-Site Scripting in AES BOM Viewer CVSS 3.1MEDIUM 6.8

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences