Unauthenticated code execution via NIS path traversal
Published Jun 5, 2026 · Updated Jun 5, 2026
Path traversal in Altium On-Prem Enterprise Server NIS before 8.1.1 allows remote attackers to write and read files on the server. Two NIS file operations fail to constrain attacker-supplied paths, enabling writes outside intended directories and reads of deployment package archives. No authentication, session, or credentials are required; writes to web directories, application binaries, or configuration files enable code execution as the service account.
Summary
What happened
Path traversal in Altium On-Prem Enterprise Server NIS before 8.1.1 allows remote attackers to write and read files on the server. Two NIS file operations fail to constrain attacker-supplied paths, enabling writes outside intended directories and reads of deployment package archives. No authentication, session, or credentials are required; writes to web directories, application binaries, or configuration files enable code execution as the service account.
The record
- CVE
- CVE-2026-11420
- Published
- Jun 5, 2026
- Updated
- Jun 5, 2026
- Vendor
- Altium
- Product
- Altium On-Prem Enterprise Server
- Classifications
- CWE-22, CWE-306, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 5, 2026CVE publishedPublication date reported by the CVE source.
- Jun 5, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <8.1.1
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo