CVE-2026-13201

Summary

A flaw was found in KubeVirt's safepath package used by virt-handler. The OpenAtNoFollow function uses O_PATH|O_NOFOLLOW to obtain a file descriptor to a path leaf, but downstream operations resolve the path via /proc/self/fd/N using link-following syscalls. When the leaf is a symlink, the kernel dereferences it, defeating the intended no-follow protection. An attacker with access to a virt-launcher pod can exploit this to redirect virt-handler's IPC socket connections, including the notify socket used for VM domain lifecycle events. By hijacking this socket, the attacker can inject arbitrary domain events into virt-handler, causing it to take incorrect lifecycle actions, corrupt VM state in the Kubernetes API, or crash — resulting in sustained denial of VM management services for all virtual machines on the affected node. Additionally, the same symlink following flaw allows virt-handler to apply file ownership or permission changes to unintended host paths.

Affected Software

VendorProductVersion RangeStatus

Weaknesses

  • CWE-61: UNIX Symbolic Link (Symlink) Following

Workarounds

The following measures reduce the attacker pool and limit secondary impact:

Review RBAC policies to restrict pods/exec permissions on virt-launcher pods to only those users who strictly require it. This reduces the number of identities that can place symlinks in the launcher filesystem. Ensure SELinux is in enforcing mode (default in OpenShift). While SELinux does not prevent the notify socket hijacking path, it restricts the set of host files targetable through the chown/chmod path by blocking operations on files with protected security labels. RHCOS immutable filesystem layers prevent modification of core OS files through the chown/chmod path. Note: no mitigation currently addresses the notify socket hijacking vector. The attacker's ability to inject domain events into virt-handler is not constrained by SELinux or filesystem immutability.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References