Linux Kernel Flaw CVE-2026-43502 Lets Local Attackers Gain Root Access

A critical local privilege escalation vulnerability, dubbed ZcopyReaper and tracked as CVE-2026-43502, was publicly disclosed in September 2026 in the Linux kernel's RDS zerocopy send path. The flaw stems from improper memory reference handling during send operations, which can lead to memory corruption and ultimately kernel-level code execution. A local attacker — such as one who has gained initial access via phishing or a stolen credential — could exploit it to obtain full root privileges on the affected host. On multi-tenant systems, the risk is especially severe, as a single compromised account could expose all tenants sharing the server. Users are advised to apply the relevant kernel patch through their distribution's update channel and reboot immediately, or alternatively block the RDS kernel module from loading if patching is not immediately possible.