VulnerabilityDeferred

CVE-2026-120308

A Beta9 tenant can attach a volume when deploying a function, endpoint, or task queue.

CRITICAL 9.9EPSS 0.53%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.53%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1: 9.9 CRITICALCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS: 0.53% probability · 45th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-22, CWE-668
Source: reefs@jfrog.com

EPSS trend

EPSS moved from 0.5% on 2 November 2026 to 0.5% on 3 November 2026.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.