# CVE-2026-121876: systemd-gpt-auto-generator credential disclosure in OpenShift Sandboxed Containers

Source: https://junglewise.ai/threats/cve-2026-121876-a-flaw-was-found-in-the-interaction-between-systemd-gpt-auto  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-12. Updated: 2026-11-12  
License: CC BY 4.0 with a link back

CVE-2026-121876 · Severity: high · CVSS 7.9 · Published 2026-11-12

OpenShift Sandboxed Containers uses lightweight virtual machines to isolate containerized workloads with hardware-enforced confidentiality guarantees. A flaw in systemd-gpt-auto-generator automatically mounts disk partitions without verification, allowing a malicious host to inject a swap partition and force the guest kernel to write encrypted memory to the host, completely bypassing the confidentiality protection that the hardware TEE (AMD SEV-SNP, Intel TDX) is supposed to provide.

Vendors: [Red Hat](https://junglewise.ai/threats/vendors/red-hat).

## Quick answers

**Is CVE-2026-121876 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-121876 being exploited in the wild.

**How severe is CVE-2026-121876?** High severity, with a CVSS score of 7.9, published 12 November 2026.

**Which products and versions are affected?** Red Hat OpenShift Sandboxed Containers confidential peer pods; Red Hat systemd-udev (RHEL) all versions shipped with RHEL.

**Is there a fix for CVE-2026-121876?** No fixed version is recorded yet. Add systemd.gpt_auto=0 to the measured kernel command line in the UKI addon to completely disable systemd-gpt-auto-generator. Alternatively, disable swap specifically with systemd.swap=0, mask the generator via ln -sf /dev/null /etc/systemd/system-generators/systemd-gpt-auto-generator, include PCR 5 in PodVM measurement, or for systemd 254+, set restrictive image policy via systemd.image_policy=root=verity+signed+encrypted+unprotected+absent:swap=absent:home=absent:srv=absent:var=absent:tmp=absent. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-121876 attacked?** It is attacked with local access, in a network appliance.

**Am I affected by CVE-2026-121876?** Check whether you run Red Hat OpenShift Sandboxed Containers or Red Hat systemd-udev (RHEL) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix


Add systemd.gpt_auto=0 to the measured kernel command line in the UKI addon to completely disable systemd-gpt-auto-generator. Alternatively, disable swap specifically with systemd.swap=0, mask the generator via ln -sf /dev/null /etc/systemd/system-generators/systemd-gpt-auto-generator, include PCR 5 in PodVM measurement, or for systemd 254+, set restrictive image policy via systemd.image_policy=root=verity+signed+encrypted+unprotected+absent:swap=absent:home=absent:srv=absent:var=absent:tmp=absent.

## Technical details

systemd-gpt-auto-generator automatically discovers and mounts GPT partitions by type GUID at boot with no user confirmation. In confidential VMs, the host/hypervisor is the adversary; it can inject a swap partition into the guest's virtual disk, causing the kernel to page out TEE-encrypted memory to a host-controlled block device. The dm-verity root partition protection and PCR measurement (3, 9, 11, 12) do not cover non-root partitions or the GPT partition table (PCR 5), leaving the guest vulnerable to partition table modification attacks.

## Affected products

- Red Hat OpenShift Sandboxed Containers confidential peer pods
- Red Hat systemd-udev (RHEL) all versions shipped with RHEL

## Timeline

- 2026-11-12: disclosed

## References

- [https://access.redhat.com/downloads/content/package-browser/](https://access.redhat.com/downloads/content/package-browser/)
- [https://access.redhat.com/security/cve/CVE-2026-121876](https://access.redhat.com/security/cve/CVE-2026-121876)