CVE-2026-56111

CVE-2026-56111 - Marlin M421 Out-of-bounds Write Proof of concept for CVE-2026-56111 , an out-of-bounds write in the M421 G-code handler of Marlin Firmware when built with MESHBEDLEVELING. Advisory: https://www.vulncheck.com/advisories/marlin-firmware-out-of-bounds-write-via-m421-g-code-handler...

PT-2026-51836

Marlin Firmware through 2.1.2.7, fixed in commit 1f255d1, when built with MESH BED LEVELING enabled, contains an out-of-bounds write vulnerability in the M421 G-code handler that allows attackers to corrupt firmware memory by supplying out-of-range X and Y grid indices. Attackers can send a singl...