File API Vulnerability in Beta9 Worker by Beam Cloud
CVE-2026-120307

9.9CRITICAL

Key Information:

Vendor

Beam-cloud

Status
Beta9 Worker
Vendor
CVE Published:
1 November 2026

What is CVE-2026-120307?

A vulnerability in the Beta9 worker allows unauthorized access to the host filesystem due to improper handling of sandbox file operations. The worker serves sandbox file API paths from outside the container, enabling a malicious tenant to exploit the getHostPathFromContainerPath function. This can lead to unrestricted read and write access to files on the host machine, including sensitive files belonging to other tenants. A proof-of-concept has shown that it is possible to download service account tokens with cluster-admin privileges. This issue has been addressed in worker version 0.1.756, which restricts file operations within the container root to prevent such attacks.

Affected Version(s)

Beta9 worker 0 < 0.1.756

References

https://github.com/beam-cloud/beta9
product
https://github.com/beam-cloud/beta9/pull/1897
patch
https://github.com/beam-cloud/beta9/commit/a28bf12cf0007c...
patch

CVSS V3.1

Score:
9.9
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Natan Nehorai
JFrog Security Research
.