Path Traversal in Altium Enterprise Server Collaboration Service Allows Privilege Escalation

published 2026-06-05 5 mo ago modified 2026-07-23 3 mo ago also EUVD-2026-34915

cvss: 9.4; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 25%
public exploits: 0; none known

A path traversal vulnerability exists in the Altium Enterprise Server Collaboration Service due to improper handling of user-supplied filenames in the MCAD and Simulation file download flows. A regular authenticated user can submit a collaboration message containing a crafted filename, which is later used to construct the download path on the server without validation, allowing arbitrary files to be read from the server filesystem.

Because the readable files include the server's master configuration, which stores credentials for privileged accounts, exploitation can lead to authenticating as a system administrator and gaining full control of the server. Altium 365 cloud deployments are not affected.

Patch / fix

fixed in 1

Altium Altium Enterprise Server 8.1.1

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 5 mo ago (2026-06-08)

Exploit prediction

0.32% chance of exploitation in the next 30 days, higher than 25% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	9.4	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
CNA	4.0	9.4	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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

Affected products

Altium Altium Enterprise Server

Classification

Weakness

CWE-22 Improper Limitation of a Pathname to a Restricted Directory
CWE-269 Improper Privilege Management

References

altium.com /platform/security-compliance/security-advisories

Sources

CVE List CVE-2026-11423
NVD CVE-2026-11423

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary