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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-56111 Detail

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.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  VulnCheck
CVSS-B 8.3 HIGH
Vector:  CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/MarlinFirmware/Marlin/commit/1f255d16ec2d456454fd444494cfb338d62b0fa1 VulnCheck
https://github.com/MarlinFirmware/Marlin/issues/28467 VulnCheck
https://github.com/MarlinFirmware/Marlin/pull/28468 VulnCheck
https://www.vulncheck.com/advisories/marlin-firmware-out-of-bounds-write-via-m421-g-code-handler VulnCheck

Weakness Enumeration

CWE-ID CWE Name Source
CWE-129 Improper Validation of Array Index VulnCheck  

Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-56111
NVD Published Date:
06/24/2026
NVD Last Modified:
06/24/2026
Source:
VulnCheck