Linux kernel versions 5.10.263 and 5.15.214 were released on August 6, 2026, featuring a critical patch addressing a vulnerability in the Safe-RET mitigation for AMD's Speculative Return Stack Overflow attacks. This flaw allowed local attackers to bypass protections by injecting precisely timed interrupts, leading to potential data leaks from Zen 1 through Zen 4 processors. The patch, co-developed by AMD researchers, ensures that the register state completes correctly and prevents return instructions from executing post-interrupt, effectively closing the exploitation window. Administrators are urged to update their systems immediately and ensure their AMD microcode is current, as the underlying CPU firmware must work in conjunction with the kernel's mitigation to maintain security

Linux Kernel LTS 5.10.263 and 5.15.214 Ship Urgent Patch for AMD Safe-RET Flaw

Greg Kroah-Hartman shipped Linux 5.10.263 and 5.15.214 on August 6, 2026, with a single critical patch that closes a flaw in the kernel's Safe-RET mitigation for AMD's Speculative Return Stack Overflow attacks. Researchers discovered that local attackers could inject precisely timed interrupts during the protective sequence, effectively bypassing the safeguard on Zen 1 through Zen 4 processors and enabling speculative side-channel data leaks. The upstream commit forces the register state to complete cleanly regardless of interrupt timing and blocks return instructions from executing afterward, effectively sealing the bypass window. Administrators should update immediately and verify their AMD microcode is current, as the underlying CPU firmware still needs to cooperate with the kernel's hardened mitigation.

Linux Kernel LTS 5.10.263 and 5.15.214 Ship Urgent Patch for AMD Safe-RET Flaw @ Linux Compatible