Beta9 host filesystem exposure via volume path traversal (beam-cloud Beta9 gateway)

CVE-2026-120308
CRITICAL 9.9

At a glance

Source
CVE.org
State
PUBLISHED
Published
Updated
Assigner
JFROG

Description

A Beta9 tenant can attach a volume when deploying a function, endpoint, or task queue. The gateway builds the host path by joining the shared volumes root, the workspace name, and the volume identifier from the stub configuration. Nothing checks that the identifier names a volume that workspace owns. Parent-directory segments in the identifier collapse the joined path to the worker's filesystem root, and the worker bind-mounts that path into the sandbox read-write unless the volume was explicitly marked read-only. A tenant with a workspace token can therefore read and write the worker's files, including other tenants' volumes stored on that machine. Confirmed against gateway 0.1.769 and worker 0.1.745. Fixed in gateway 0.1.776 and worker 0.1.756: volume identifiers and mount paths are validated before a mount is built, including for stubs saved before the check existed, and the gateway rejects a volume that does not exist or is not owned by the workspace.

Weaknesses (CWE)

  • CWE-22 β€” Improper Limitation of a Pathname to a Restricted Directory
  • CWE-668 β€” Exposure of Resource to Wrong Sphere

References

Scores

VersionScoreVectorScored by
CVSS 3.1CRITICAL 9.9CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HJFROG

European references

Affected products

ProductVersions
beam-cloud Β· Beta9 gatewayaffected 0 < 0.1.776
beam-cloud Β· Beta9 workeraffected 0 < 0.1.756

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
ENISA EUVDENISA β€” reproduction authorised, source acknowledged