CVE-2026-3842

A flaw was found in QEMU. This vulnerability allows a local attacker within a guest virtual machine to write data beyond its allocated memory. This occurs when cpu_physical_memory_map() returns a shorter length than expected, leading to an out-of-bounds write. Successful exploitation could result in unauthorized access to guest memory or corruption of heap-allocated objects, potentially causing information disclosure, data integrity issues, or a denial of service.

The qemu-kvm packages as shipped with Red Hat Enterprise Linux are not affected by this CVE. The Hyper-V Synthetic Debugging device (syndbg.c) is disabled at build-time in RHEL, effectively removing the attack surface.

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.