Path Traversal in Altium Enterprise Server ComparisonService Allows Arbitrary File Write

published 2026-05-20 5 mo ago modified 2026-07-23 3 mo ago also EUVD-2026-31146

cvss: 9.4; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.6%; EPSS 0.6% chance of exploitation in 30 days, percentile 47%
public exploits: 0; none known

A path traversal vulnerability exists in the Altium Enterprise Server ComparisonService due to missing filename sanitization in the Gerber file upload APIs. A regular authenticated workspace user can supply a crafted filename in the multipart Content-Disposition header to escape the intended temporary upload directory and write arbitrary files to any location on the server filesystem.

Because content-controlled files can be written to web-accessible directories, this can be escalated to remote code execution in the context of the service account. It can also be used to overwrite application binaries or configuration files, leading to service takeover or denial of service.

Patch / fix

fixed in 1

Altium Altium Enterprise Server 8.0.4

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 5 mo ago (2026-05-20)

Exploit prediction

0.56% chance of exploitation in the next 30 days, higher than 47% 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-434 Unrestricted Upload of File with Dangerous Type

References

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

Sources

CVE List CVE-2026-9102
NVD CVE-2026-9102

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