{"cve":{"cve_id":"CVE-2020-12526","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":0.00955,"epss_percentile":0.56761,"epss_as_of":"2026-06-23","description":"TwinCAT OPC UA Server in versions up to 2.3.0.12 and IPC Diagnostics UA Server in versions up to 3.1.0.1 from Beckhoff Automation GmbH & Co. KG are vulnerable to denial of service attacks. The attacker needs to send several specifically crafted requests to the running OPC UA server. After some of these requests the OPC UA server is no longer responsive to any client. This is without effect to the real-time functionality of IPCs.","published_at":"2021-05-13T13:45:24.098000Z","last_modified_at":null,"cvss_v3_score":5.3,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","cvss_v3_severity":"MEDIUM","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":["CWE-20"],"nvd_references":["https://cert.vde.com/en-us/advisories/vde-2020-051","https://download.beckhoff.com/download/Document/product-security/Advisories/advisory-2021-001.pdf"],"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":"2026-06-24T00:09:39.878444Z","updated_at":"2026-06-28T23:13:23.491019Z"},"effective_severity":"MEDIUM","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":"N","value_label":"None"},{"metric":"A","name":"Availability","value":"L","value_label":"Low"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"beckhoff","vendor_name":"Beckhoff","product_slug":"ipc-diagnostics-ua-server","product_name":"IPC Diagnostics UA Server","version_start":"unspecified","version_start_inclusive":true,"version_end":"3.1.0.1","version_end_inclusive":true,"cpe23_uri":"cve5:beckhoff:ipc-diagnostics-ua-server:unspecified:3.1.0.1"},{"vendor_slug":"beckhoff","vendor_name":"Beckhoff","product_slug":"tf6100","product_name":"TF6100","version_start":"unspecified","version_start_inclusive":true,"version_end":"3.3.18","version_end_inclusive":true,"cpe23_uri":"cve5:beckhoff:tf6100:unspecified:3.3.18"},{"vendor_slug":"beckhoff","vendor_name":"Beckhoff","product_slug":"twincat-opc-ua-server","product_name":"TwinCAT OPC UA Server","version_start":"unspecified","version_start_inclusive":true,"version_end":"2.3.0.12","version_end_inclusive":true,"cpe23_uri":"cve5:beckhoff:twincat-opc-ua-server:unspecified:2.3.0.12"}],"exploit_refs":[],"news":[],"references":[{"url":"https://cert.vde.com/en-us/advisories/vde-2020-051","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://download.beckhoff.com/download/Document/product-security/Advisories/advisory-2021-001.pdf","source_type":"VENDOR_ADVISORY","tags":["advisory"]}],"timeline":[{"type":"published","at":"2021-05-13T13:45:24.098000Z","label":"CVE published","source":null},{"type":"cvss_changed","at":"2026-06-28T17:02:09.360524Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:02:09.360524Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:02:09.360524Z","label":"CVSS score revised","source":"cvelistv5"}]}