CVE-2026-120306: beam-cloud Beta9 worker · Improper Isolation or Compartmentalization
Affects beam-cloud Beta9 workerSource CVE Database V5
Not known to be exploited · CVSS 9.9 Critical : upgrade to 0.1.756 as a priority.
Data as of 1 Nov 2026, 13:13 UTC
Thin evidence
One scorer or none| CNA (JFROG) | CVSS 3.1 | 9.9 |
|---|
- Patch
- Available – fixed in 0.1.756
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 1 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 1 Nov 2026.
What to do
Upgrade Beta9 worker and github.com/beam-cloud/beta9 to 0.1.756.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Beta9 workergithub.com/beam-cloud/beta9 | Affected
| Fixed in
|
GitHubgithub.com/beam-cloud/beta9pkg:github/github.com/beam-cloud/beta9Other threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fixed version 0.1.756 of the Beta9 worker is available that addresses this vulnerability by using OCI isolation with private PID, IPC, and network namespaces for Buildah RUN steps and restricting tenant ARG values. Users should upgrade to version 0.1.756 or later to remediate this issue. No additional mitigations are indicated by the vendor advisory.
Description
CVE-2026-120306 is a critical vulnerability in the beam-cloud Beta9 worker component. The issue arises because Buildah RUN steps execute with chroot isolation, sharing PID, network, IPC, and user namespaces with the privileged worker pod, which runs as root and holds CAP_DAC_OVERRIDE. This improper isolation allows tenant builds to access sensitive host resources, including the worker's binaries, Kubernetes service account token, and mounted host directories. The vulnerability is fixed in version 0.1.756 by switching to OCI isolation with private namespaces and restricting tenant ARG values.