LearnCTEM.com, Best CTEM Learning Platform
CVE Intelligence Hub

CVE-2026-121876: Red Hat interaction between systemd-gpt-auto-generator and confidential computing guest VM images in OpenShift Sandboxed Containers (confidential peer pods) Security Vulnerability

CVE-2026-121876 explained: high Security Vulnerability in Red Hat interaction between systemd-gpt-auto-generator and confidential computing guest VM images in OpenSh

Last updated: Nov 12, 2026

CVSS
7.9 HIGH
EPSS
n/a
CISA KEV
Not listed
CWE
CWE-359

Sources: National Vulnerability Database, CVE.org, CISA KEV, FIRST EPSS

CVE-2026-121876 Overview

A flaw was found in the interaction between systemd-gpt-auto-generator and confidential computing guest VM images in OpenShift Sandboxed Containers (confidential peer pods). systemd-gpt-auto-generator automatically discovers and mounts GPT partitions by type GUID at boot with no user confirmation. In the confidential computing threat model, where the host/hypervisor is the adversary, a malicious host can inject partitions into the guest's virtual disk. Most critically, injecting a swap partition causes the guest kernel to page out TEE-encrypted memory to a host-controlled block device, breaking the confidentiality guarantee of the hardware TEE (AMD SEV-SNP, Intel TDX). The PodVM images use a GPT-partitioned disk with dm-verity on the root partition. However, the roothash= kernel parameter only disables root auto-discovery — non-root partitions (swap, /home, /var, /srv, /var/tmp) are still auto-discovered and mounted. The generator is shipped unmasked in the RHEL systemd-udev subpackage, and no kernel command line parameter in the measured UKI addon disables it. Additionally, the PodVM measurement script captures PCRs 3, 9, 11, and 12, but not PCR 5 (GPT partition table), so partition table modifications are not detected by remote attestation.

Critical Impact

Local or adjacent, authenticated attackers can exploit this Security Vulnerability in Red Hat interaction between systemd-gpt-auto-generator and confidential computing guest VM images in OpenShift Sandboxed Containers (confidential peer pods). The CVSS base score is 7.9 (High).

Affected Products

  • Red Hat interaction between systemd-gpt-auto-generator and confidential computing guest VM images in OpenShift Sandboxed Containers (confidential peer pods): see the vendor advisory for the exact affected versions

Discovery Timeline

  • 2026-11-12: CVE-2026-121876 published to the National Vulnerability Database by secalert@redhat.com
  • 2026-11-12: last updated in the NVD database

Technical Details for CVE-2026-121876

Vulnerability Analysis

CVE-2026-121876 is a Security Vulnerability weakness (CWE-359) in Red Hat interaction between systemd-gpt-auto-generator and confidential computing guest VM images in OpenShift Sandboxed Containers (confidential peer pods). Based on its CVSS vector, the flaw needs local or adjacent access, needs some level of access, and needs no user interaction.

With a CVSS base score of 7.9, apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Root Cause

The vendor description states: A flaw was found in the interaction between systemd-gpt-auto-generator and confidential computing guest VM images in OpenShift Sandboxed Containers (confidential peer pods). systemd-gpt-auto-generator automatically discovers and mounts GPT partitions by type GUID at boot with no user confirmation. In the confidential computing threat model, where the host/hypervisor is the adversary, a malicious host can inject partitions into the guest's virtual disk. Most critically, injecting a swap partition causes the guest kernel to page out TEE-encrypted memory to a host-controlled block device, breaking the confidentiality guarantee of the hardware TEE (AMD SEV-SNP, Intel TDX). The PodVM images use a GPT-partitioned disk with dm-verity on the root partition. However, the roothash= kernel parameter only disables root auto-discovery — non-root partitions (swap, /home, /var, /srv, /var/tmp) are still auto-discovered and mounted. The generator is shipped unmasked in the RHEL systemd-udev subpackage, and no kernel command line parameter in the measured UKI addon disables it. Additionally, the PodVM measurement script captures PCRs 3, 9, 11, and 12, but not PCR 5 (GPT partition table), so partition table modifications are not detected by remote attestation.

Attack Vector

Based on the CVSS vector, the flaw needs local or adjacent access, needs some level of access, and needs no user interaction. Attack complexity is low complexity.

No exploitation in the wild is confirmed by CISA at the time of the last update. Check the references below for any vendor or researcher proof of concept.

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N

Detection Methods for CVE-2026-121876

Detection Strategies

  • Inventory every instance of Red Hat interaction between systemd-gpt-auto-generator and confidential computing guest VM images in OpenShift Sandboxed Containers (confidential peer pods) and compare the running version with the affected range above.
  • Check external attack surface scans for internet facing instances of the component.
  • Run an authenticated vulnerability scan once your scanner ships a check for this CVE.

Monitoring Recommendations

  • Forward Red Hat interaction between systemd-gpt-auto-generator and confidential computing guest VM images in OpenShift Sandboxed Containers (confidential peer pods) application, access and audit logs to your SIEM for retrospective hunting.
  • Alert on new processes, configuration changes or outbound connections from the affected service.
  • Track the vendor advisory and the CISA KEV catalog for changes in exploitation status.

How to Mitigate CVE-2026-121876

Immediate Actions Required

  • Apply the fixed version of Red Hat interaction between systemd-gpt-auto-generator and confidential computing guest VM images in OpenShift Sandboxed Containers (confidential peer pods) named in the vendor advisory.
  • Prioritize internet facing and business critical instances first.
  • Rescan after the change to confirm the exposure is closed.

Patch Information

Use the fixed version listed in the vendor advisory for Red Hat interaction between systemd-gpt-auto-generator and confidential computing guest VM images in OpenShift Sandboxed Containers (confidential peer pods).

Workarounds

  • If patching must wait, restrict network access to the affected service and place it behind authentication or a web application firewall rule.

CWE References

Technical References

This entry is built directly from NVD, CISA KEV and EPSS data. Verify fixed versions in the vendor advisory before you deploy.

Frequently asked questions

CVE-2026-121876 is a high severity Security Vulnerability in Red Hat interaction between systemd-gpt-auto-generator and confidential computing guest VM images in OpenShift Sandboxed Containers (confidential peer pods) with a CVSS score of 7.9. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Related CVEs

HIGH7.5
CVE-2026-127030
Red Hat freeradius

A flaw was found in freeradius. An improper length validation in the EAP-FAST module allows a stack-based buffer overflow during session ticket processing. A remote, unauthenticated attacker can exploit this flaw by sending a specially crafted handshake request, causing the server process to crash and resulting in a Denial of Service (DoS).

Nov 12, 2026
HIGH7.5
CVE-2026-127029
Red Hat freeradius's Extensible Authentication Protocol Method for Subscriber Identity Module (EAP-SIM) module

A flaw was found in freeradius's Extensible Authentication Protocol Method for Subscriber Identity Module (EAP-SIM) module. When handling authentication requests, the server copies a client-supplied identity into an internal structure without properly checking its length against a fixed-size buffer. An unauthenticated remote attacker can exploit this issue by sending specially crafted EAP-SIM messages, triggering a stack buffer overflow that crashes the service and results in a Denial of Service (DoS).

Nov 12, 2026
HIGH7.2
CVE-2026-125637
Red Hat Konflux UI proxy

A flaw was found in the Konflux UI proxy. Hostname values defined in the KonfluxUI custom resource are inserted directly into proxy configuration files without adequate validation or sanitization. An authenticated user with permissions to modify the custom resource can inject malicious configuration directives to bypass authentication and authorization controls, potentially exposing internal backend services. In addition, providing malformed input can cause the configuration generator to fail, resulting in a denial of service (DoS) by preventing the proxy from starting.

Nov 11, 2026
HIGH7.3
CVE-2026-91151
Red Hat Cockpit

A flaw was found in Cockpit. A local authenticated user with control over a target account's home directory can exploit a privileged symlink dereference vulnerability in the `ssh-add-public-key.sh` helper. When this helper runs with elevated privileges, it can be tricked into following attacker-controlled symlinks within the `.ssh` or `authorized_keys` paths. This allows the attacker to arbitrarily change file ownership and modes, potentially leading to local privilege escalation and impacting the integrity, confidentiality, and availability of the system.

Nov 11, 2026
HIGH7.5
CVE-2026-91150
Red Hat Cockpit

A flaw was found in Cockpit. This vulnerability allows a remote attacker, without prior authentication, to send specially crafted fragmented WebSocket messages. These messages accumulate without a total-size limit, leading to unbounded memory exhaustion and a denial of service in the `cockpit-ws` service.

Nov 11, 2026
HIGH7.3
CVE-2026-123747
Red Hat pappl-retrofit

A flaw was found in pappl-retrofit. The application fails to properly sanitize user-supplied filenames when handling the upload and deletion of PostScript Printer Description (PPD) files. A remote, unauthenticated attacker can exploit this directory traversal flaw by submitting filenames containing path traversal sequences. This allows the attacker to upload or delete arbitrary files on the system, which can result in data corruption, denial of service, or arbitrary command execution.

Nov 11, 2026
All Red Hat CVEs in 2026
Your next credential

Earn your free CTEM certification.

Learn to scope, prioritize, validate and mobilize fixes for CVEs like CVE-2026-121876 with a free CTEM certification.

Free to takePublicly verifiable

Beginner / Practitioner / Program Leader

Explore certifications