CVE-2026-56111
CRITICALMarlin Firmware 2.1.2.7 Out-of-Bounds Write via M421 G-code Handler
Title source: cnaExploitation Summary
EIP tracks 1 public exploit for CVE-2026-56111. PoCs published by Christbowel.
AI-analyzed exploit summary The repository contains a functional exploit for CVE-2026-56111, an out-of-bounds write vulnerability in Marlin Firmware's M421 G-code handler. The exploit allows controlled writes past the z_values array, leading to denial-of-service or potential memory corruption.
Description
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 single crafted G-code command via USB serial, network interface, or malicious gcode file to write an attacker-controlled 32-bit float value past the z_values array bounds, corrupting adjacent firmware variables and causing denial of service or firmware state corruption.
Exploits (1)
The repository contains a functional exploit for CVE-2026-56111, an out-of-bounds write vulnerability in Marlin Firmware's M421 G-code handler. The exploit allows controlled writes past the z_values array, leading to denial-of-service or potential memory corruption.
References (4)
Scores
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H