CVE-2026-89766

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An issue exists in the pidfd ioctl() function where PIDFD GET * NAMESPACE ioctls perform a filesystem credentials ptrace access check without holding the target task's exec update lock. This differs from the behavior of procfs paths. Consequently, a caller could pass the access check using a target's old credentials and then read the namespace after the target has executed a setuid binary and committed new credentials, allowing unauthorized access to namespace information.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.