CVE-2026-11420 Path Traversal in Altium Enterprise Server NIS Allows Unauthenticated Arbitrary File Write and File Read
Unauthenticated attackers can exploit path traversal in Altium Enterprise Server to write arbitrary files and read archives, potentially achieving remote code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-11420?
CVE-2026-11420 is a critical path traversal vulnerability in Altium Enterprise Server, published on 5 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-11420?
It affects 1 product.
Products include Altium On-Prem Enterprise Server.
How do I fix CVE-2026-11420?
No fix has been published for CVE-2026-11420 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-11420 being exploited?
There is no known exploitation of CVE-2026-11420 in the wild and no public exploit code.
Other vulnerabilities in Altium Enterprise Server
- CVE-2026-11414 Hardcoded credentials in Altium Enterprise Server
- CVE-2026-11419 Path Traversal in Altium Enterprise Server Vault UploadController Allows Arbitrary File Write
- CVE-2025-27378 SQL Injection in AES Due to Inactive SQL Parsing Configuration
- CVE-2026-1010 Stored Cross-Site Scripting in Altium Enterprise Server Workflow Engine Allows Privilege Escalation
- CVE-2025-27380 HTML Injection Leading to Script Execution in Altium Enterprise Server
Sources
Also known as GHSA-q58x-mgvc-jhw9.