CVE-2026-56111

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Source

https://cve.org/CVERecord?id=CVE-2026-56111

Import Source

https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-56111.json

JSON Data

https://api.osv.dev/v1/vulns/CVE-2026-56111

Published

2026-06-24T14:31:04Z

Modified

2026-10-28T10:57:58Z

Severity

8.3 (High) CVSS_V4 - 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 CVSS Calculator

Summary

Marlin Firmware 2.1.2.7 Out-of-Bounds Write via M421 G-code Handler

Details

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.

Database specific

{
    "cna_assigner":  "VulnCheck",
    "cwe_ids":  [
        "CWE-129"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56111.json"
}

References

Affected packages

Git / github.com/marlinfirmware/marlin

Affected ranges

Type

GIT

Repo

https://github.com/marlinfirmware/marlin

Events

Introduced

Fixed

1f255d16ec2d456454fd444494cfb338d62b0fa1

Database specific

Show details

{
    "extracted_events":  [
        {
            "range":  [
                {
                    "introduced":  "0"
                },
                {
                    "last_affected":  "2.1.2.7"
                }
            ],
            "source":  "AFFECTED_FIELD",
            "strategy":  "StandardRange"
        },
        {
            "range":  [
                {
                    "fixed":  "1f255d16ec2d456454fd444494cfb338d62b0fa1"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        }
    ]
}

Affected versions

1.*

1.0.0-beta

1.0.1

1.1.0-RC3

1.1.0-RC4

dev-2.*

dev-2.1.3-b1

dev-2.1.3-b2

dev-2.1.3-b3

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-56111.json"

vanir_signatures

[
    {
        "deprecated":  false,
        "digest":  {
            "line_hashes":  [
                "65084144221909310942370447431265322160",
                "175907672631708315228212289292572651484",
                "147031761490418648937213108883542478042",
                "204959399880849597872883576694047224689"
            ],
            "threshold":  0.9
        },
        "id":  "CVE-2026-56111-9adc8e13",
        "signature_type":  "Line",
        "signature_version":  "v1",
        "source":  "https://github.com/marlinfirmware/marlin/commit/1f255d16ec2d456454fd444494cfb338d62b0fa1",
        "target":  {
            "file":  "Marlin/src/gcode/bedlevel/mbl/M421.cpp"
        }
    },
    {
        "deprecated":  false,
        "digest":  {
            "function_hash":  "65593862883820517918883272994487778399",
            "length":  850
        },
        "id":  "CVE-2026-56111-9ee64fc1",
        "signature_type":  "Function",
        "signature_version":  "v1",
        "source":  "https://github.com/marlinfirmware/marlin/commit/1f255d16ec2d456454fd444494cfb338d62b0fa1",
        "target":  {
            "file":  "Marlin/src/gcode/bedlevel/mbl/M421.cpp",
            "function":  "GcodeSuite::M421"
        }
    }
]

vanir_signatures_modified

"2026-10-28T10:57:58Z"