VULNERABILITY INTELLIGENCE
CVE-2026-56111
CVSS score9.1 CRITICAL
EPSS probability0.65%
CISA KEVNot currently listed
Published2026-06-24
Last modified2026-10-25
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
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.
Weakness classification
- disclosure@vulncheck.com: CWE-129