Home/CVE/Two path traversal vulnerabilities in the Network Installation Service (NIS) of Altium Enterprise Server allow an unauth
CVE

CVE-2026-11420

Two path traversal vulnerabilities in the Network Installation Service (NIS) of Altium Enterprise Server allow an unauth

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.

EPSS 0.00805
Schedule remediation
  • SSVC automatable: yes - attacks can be scripted at scale
  • ⚠ NVD has not scored this CVE yet - manual triage required (common for recent CVEs)
Sigma rules0 YARA rules0
Look this up elsewhere - one-click external pivots
NVDCVE.orgCISAVulnersExploit-DBGitHub PoCVulnCheck KEVGreyNoise
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This page is every public fact about CVE-2026-11420, cross-linked. Its job is to answer one question fast - does this need my attention now? - and then hand you the two things you do about it. Here is how an analyst reads it.
Triage: should I act now? Four signals, and they are not interchangeable:
CVSSseverity - how bad it is IF exploited, 0-10. A high CVSS alone is not urgency; a flaw can be a perfect 10 and never actually be attacked. EPSSprobability - a model’s estimate of the chance it is exploited in the next 30 days, 0-1. This is the “will it actually happen” signal. CISA KEVconfirmed - it is being exploited in the wild right now. The strongest signal on the page; KEV beats any score. Weaponisedavailability - public exploits / PoCs, and especially Metasploit modules rated Excellent / Great. Reliable, packaged exploit code means low-skill attackers can use it today.
How they combine: KEV, or a dependable Metasploit module, means patch now regardless of CVSS. High CVSS + low EPSS + no exploit is real but not an emergency - schedule it. Low CVSS but KEV-listed still gets patched now. The verdict above already weighed these for you; this is how it got there.
Then what - two workflows:
Detectwhen you cannot patch today, follow this CVE to the ATT&CK techniques it enables, then Build a SIEM detection (the green button) - author a rule, test it in Atomic, deploy it. That buys visibility while the patch waits. PatchAffected products / packages tell you if you are exposed; Fixed versions by distribution and Vendor advisories give the exact version that closes it.
Reading order for the panels below: verdict + badges, then Public exploits / Metasploit (is it weaponised), then ATT&CK techniques + Sigma / IDS rules (can I detect it), then Affected products / packages + Fixed versions (am I exposed, what patches it), then Threat actors / IOCs (who uses it), then Scoring & timeline / references (the evidence).
◆

ATT&CK techniques

3

Techniques this CVE enables - linked via CWECAPECATT&CK. High◆ = named directly in ATT&CK or Nuclei templates.

T1078 · Valid Accounts T1083 · File and Directory Discovery T1190 · Exploit Public-Facing Application
▤ Build a SIEM detection for these techniques
▤

CAPEC attack patterns

10

Attack patterns this CVE enables - the bridge from weakness to ATT&CK technique.

CAPEC-CAPEC-12 · Choosing Message Identifier CAPEC-CAPEC-126 · Path Traversal CAPEC-CAPEC-166 · Force the System to Reset Values CAPEC-CAPEC-216 · Communication Channel Manipulation CAPEC-CAPEC-36 · Using Unpublished Interfaces or Functionality CAPEC-CAPEC-62 · Cross Site Request Forgery CAPEC-CAPEC-64 · Using Slashes and URL Encoding Combined to Bypass Validation Logic CAPEC-CAPEC-76 · Manipulating Web Input to File System Calls CAPEC-CAPEC-78 · Using Escaped Slashes in Alternate Encoding CAPEC-CAPEC-79 · Using Slashes in Alternate Encoding
⬡

Weakness Classification

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CWE-306Missing Authentication for Critical Function
▣

Scoring & Timeline

Published to NVD05 Jun 2026 · 08:17 PM
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
yes
Technical impact
total
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
🔗

References & Sources

1
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://www.altium.com/platform/security-compliance/security-advisories
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