CVE-2026-120306: Beta9 turns each shell command
Affects beta9Source GCVE Database
Not known to be exploited · CVSS 9.9 Critical : upgrade to 0.1.756 as a priority.
Data as of 1 Nov 2026, 16:30 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 beam-cloud/beta9 to 0.1.756.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
GitHubbeam-cloud/beta9pkg:github/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
This vulnerability is fixed in Beta9 worker version 0.1.756. Users should upgrade to this version or later to ensure Buildah RUN steps use OCI isolation with private PID, IPC, and network namespaces. Tenant ARG values are also restricted to the build container only. No other mitigation is required once the patch is applied.
Description
CVE-2026-120306 is a critical vulnerability in Beta9's tenant image build process where shell commands in tenant image definitions are executed with insufficient isolation. The build worker runs these commands with Buildah using chroot isolation, retaining shared PID, network, IPC namespaces, and running as root with CAP_DAC_OVERRIDE. This allows tenant builds to access and potentially modify the worker container's filesystem, including sensitive binaries and Kubernetes service account tokens. The issue is fixed in worker version 0.1.756 by enforcing OCI isolation with private namespaces and restricting tenant ARG propagation.
References
- nvd.nist.gov/vuln/detail/CVE-2026-120306 (opens in a new tab)
- github.com/beam-cloud/beta9/pull/1897 (opens in a new tab)
- github.com/beam-cloud/beta9/commit/a28bf12cf0007c792a25d8ed282b4e8bf6f30393 (opens in a new tab)
- github.com/beam-cloud/beta9 (opens in a new tab)
- github.com/beam-cloud/beta9/releases/tag/worker-0.1.756 (opens in a new tab)