{"cve":{"cve_id":"CVE-2026-56111","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":null,"epss_percentile":null,"epss_as_of":null,"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.","published_at":"2026-06-24T14:31:04.284000Z","last_modified_at":null,"cvss_v3_score":9.1,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","cvss_v3_severity":"CRITICAL","cvss_v4_score":8.3,"cvss_v4_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","cvss_v4_severity":"HIGH","ssvc_decision":null,"ssvc_exploitation":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":["CWE-129"],"nvd_references":["https://github.com/MarlinFirmware/Marlin/issues/28467","https://github.com/MarlinFirmware/Marlin/pull/28468","https://github.com/MarlinFirmware/Marlin/commit/1f255d16ec2d456454fd444494cfb338d62b0fa1","https://www.vulncheck.com/advisories/marlin-firmware-out-of-bounds-write-via-m421-g-code-handler"],"vuln_status":null,"trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-28T17:55:37.240342Z","updated_at":"2026-06-28T23:30:56.588703Z"},"effective_severity":"HIGH","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"PR","name":"Privileges Required","value":"N","value_label":"None"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"U","value_label":"Unchanged"},{"metric":"C","name":"Confidentiality","value":"N","value_label":"None"},{"metric":"I","name":"Integrity","value":"H","value_label":"High"},{"metric":"A","name":"Availability","value":"H","value_label":"High"}]},"cvss_v4_decoded":{"version":"4.0","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"AT","name":"Attack Requirements","value":"P","value_label":"Present"},{"metric":"PR","name":"Privileges Required","value":"N","value_label":"None"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"VC","name":"Confidentiality (Vulnerable System)","value":"N","value_label":"None"},{"metric":"VI","name":"Integrity (Vulnerable System)","value":"H","value_label":"High"},{"metric":"VA","name":"Availability (Vulnerable System)","value":"H","value_label":"High"},{"metric":"SC","name":"Confidentiality (Subsequent System)","value":"N","value_label":"None"},{"metric":"SI","name":"Integrity (Subsequent System)","value":"N","value_label":"None"},{"metric":"SA","name":"Availability (Subsequent System)","value":"N","value_label":"None"}]},"affected":[{"vendor_slug":"marlinfirmware","vendor_name":"MarlinFirmware","product_slug":"marlin","product_name":"Marlin","version_start":"0","version_start_inclusive":true,"version_end":"2.1.2.7","version_end_inclusive":true,"cpe23_uri":"cve5:marlinfirmware:marlin:0:2.1.2.7"},{"vendor_slug":"marlinfirmware","vendor_name":"MarlinFirmware","product_slug":"marlin","product_name":"Marlin","version_start":"1f255d16ec2d456454fd444494cfb338d62b0fa1","version_start_inclusive":true,"version_end":"1f255d16ec2d456454fd444494cfb338d62b0fa1","version_end_inclusive":true,"cpe23_uri":"cve5:marlinfirmware:marlin:1f255d16ec2d456454fd444494cfb338d62b0fa1:1f255d16ec2d456454fd444494cfb338d62b0fa1"}],"exploit_refs":[],"news":[],"references":[{"url":"https://github.com/MarlinFirmware/Marlin/issues/28467","source_type":"MISC","tags":[]},{"url":"https://github.com/MarlinFirmware/Marlin/pull/28468","source_type":"PATCH","tags":["patch"]},{"url":"https://github.com/MarlinFirmware/Marlin/commit/1f255d16ec2d456454fd444494cfb338d62b0fa1","source_type":"PATCH","tags":["patch"]},{"url":"https://www.vulncheck.com/advisories/marlin-firmware-out-of-bounds-write-via-m421-g-code-handler","source_type":"VENDOR_ADVISORY","tags":["advisory"]}],"timeline":[{"type":"published","at":"2026-06-24T14:31:04.284000Z","label":"CVE published","source":null}]}