CVE-2026-47766 containers CVE debrief

Who should care

Defenders managing container runtimes, especially in local rootful environments, should assess exposure and prioritize verification and remediation due to potential for unintended device node creation outside the container rootfs and possible local privilege escalation.

Why it matters

Defenders should care about CVE-2026-47766 because it can lead to unintended device node creation outside the container rootfs in local rootful crun replays, potentially allowing local privilege escalation. Affected systems require verification, and remediation involves upgrading to crun version 1.28 or later.

• Potential for unintended device node creation outside the container rootfs
• Possible local privilege escalation in rootful environments
• Need for verification of affected systems and remediation priority

Technical summary

crun versions prior to 1.28 have a default device setup issue that can create fixed device nodes and symlinks outside the container rootfs in a local rootful crun replay. This issue arises from crun's default device setup opening the container rootfs `/dev` directory without `O_NOFOLLOW`. The issue allows for potential unintended device node creation outside the container rootfs, potentially allowing local privilege escalation. Affected systems require verification, and remediation involves upgrading to crun version 1.28 or later.

Defensive priority

Defenders should prioritize verifying and upgrading to crun version 1.28 or later, especially in local rootful environments.

Recommended defensive actions

• Verify crun version and upgrade to 1.28 or later
• Review and restrict access to local rootful crun replays
• Monitor for unusual device node creation outside the container rootfs
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record and NVD entry provide details on the issue, which is fixed in crun version 1.28. However, the scope of affected systems and potential impact require further verification and defensive actions. Defenders should verify crun versions, review and restrict access to local rootful crun replays, and monitor for unusual device node creation outside the container rootfs.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.