CVE-2026-46242

A flaw was found in the Linux kernel's eventpoll mechanism. A Use-After-Free (UAF) vulnerability, where the system attempts to access memory after it has been freed, can occur during the removal of a file. A local attacker could exploit this race condition to corrupt memory, potentially leading to privilege escalation or arbitrary code execution. This allows an attacker to gain elevated control over the system.

A race in eventpoll ep_remove() can let a concurrent file release observe a transient cleared file f_ep state and skip the normal eventpoll_release_file cleanup path. In the epoll watches epoll case this can free the watched struct eventpoll while ep_remove() still uses list pointers that refer into that freed object, so hlist_del_rcu() can write into freed kmalloc memory. This is a use-after-free memory corruption issue rather than a pure crash or resource leak. For the CVSS the AC:H is selected because reliable triggering depends on a race window between ep_remove() and __fput(). The issue is not network reachable. Impact is at least a local denial of service via kernel crash and in worst case may allow confidentiality, integrity, and availability compromise due to kernel heap memory corruption.

RHEL 9.0 and 9.2 are not affected.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.