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
2026-06-24T14:31:04.284Z
Modified
2026-08-12T16:41:25.610961Z
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 MESHBEDLEVELING 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
0 Unknown introduced commit / All previous commits are affected
Fixed
3b8ab730b259e1388646050855aa133c85a077cb
Fixed
1f255d16ec2d456454fd444494cfb338d62b0fa1
Database specific
Show details 
{
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "2.1.2.7"
        }
    ],
    "source": [
        "DESCRIPTION",
        "REFERENCES"
    ]
}

Affected versions

1.*
1.0.0-beta
1.0.1
1.1.0-RC3
1.1.0-RC4
2.*
2.0.0
2.0.1
2.0.4
2.0.4.1
2.0.4.2
2.0.4.3
2.0.4.4
2.0.5
2.0.5.1
2.0.5.2
2.0.5.3
2.0.5.4
2.0.6
2.0.6.1
2.0.7
2.0.7.1
2.0.7.2
2.0.8
2.0.8.1
2.0.8.2
2.0.9
2.0.9.1
2.0.9.2
2.0.9.3
2.0.9.4
2.1
2.1.1
2.1.2
2.1.2.1
2.1.2.2
2.1.2.3
2.1.2.4
2.1.2.5
2.1.2.6
dev-2.*
dev-2.1.3-b1
dev-2.1.3-b2
dev-2.1.3-b3

Database specific

vanir_signatures 
[
    {
        "target": {
            "file": "Marlin/src/gcode/bedlevel/mbl/M421.cpp"
        },
        "signature_type": "Line",
        "deprecated": false,
        "signature_version": "v1",
        "source": "https://github.com/marlinfirmware/marlin/commit/1f255d16ec2d456454fd444494cfb338d62b0fa1",
        "digest": {
            "threshold": 0.9,
            "line_hashes": [
                "65084144221909310942370447431265322160",
                "175907672631708315228212289292572651484",
                "147031761490418648937213108883542478042",
                "204959399880849597872883576694047224689"
            ]
        },
        "id": "CVE-2026-56111-9adc8e13"
    },
    {
        "target": {
            "function": "GcodeSuite::M421",
            "file": "Marlin/src/gcode/bedlevel/mbl/M421.cpp"
        },
        "signature_type": "Function",
        "deprecated": false,
        "signature_version": "v1",
        "source": "https://github.com/marlinfirmware/marlin/commit/1f255d16ec2d456454fd444494cfb338d62b0fa1",
        "digest": {
            "function_hash": "65593862883820517918883272994487778399",
            "length": 850.0
        },
        "id": "CVE-2026-56111-9ee64fc1"
    }
]
vanir_signatures_modified 
"2026-08-12T16:41:25Z"
source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-56111.json"