Research - From Square Root to /root: Escalating Privileges in Azure Containers with Python in Excel
Isolation is not the same thing as security.
Ron Ben Yizhak from SafeBreach Labs presented this research at Black Hat USA and DEF CON: when Microsoft shipped Python in Excel, the code didn't run on a machine. It ran in an isolated container in Azure. So he asked the obvious question. How isolated is it, really?
An isolated environment still has an attack surface. It just moves.
See how Ron:
- Escalated from a restricted user to root inside the Azure container
- Surfaced what was actually happening behind the scenes
- Uncovered a separate Excel vulnerability, now tracked as CVE-2026-45459
- Coordinated disclosure with Microsoft
If your teams are evaluating cloud-executed code features, this one is worth the full read—the methodology matters as much as the findings.
Read now: https://www.safebreach.com/blog/python-in-excel-vulnerability-root-escalation-cve-2026-45459/