Linux Kernel Vulnerability in User-Space Daemon Interaction

CVE-2026-89793

What is CVE-2026-89793?

A vulnerability in the Linux kernel allows user-space daemons to perform unauthorized memory mappings. The issue arises from the ublk driver, where mmap requests on read-only mappings retain the VM_MAYWRITE flag. Consequently, an attacker can exploit this flaw to upgrade a read-only mapping to writable using mprotect(). This results in potential corruption of critical kernel fields, which can compromise system stability and security. The vulnerability has been rectified, reinforcing the integrity of the mapping process and enhancing overall system safety.

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