{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-11857: Insecure .NET Remoting deserialization in Quanos SCHEMA ST4 Client Update Service allows local privilege escalation","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-11857","status":"final","version":"1","initial_release_date":"2026-06-17T11:42:02.012Z","current_release_date":"2026-06-17T14:56:58.522Z","revision_history":[{"date":"2026-06-17T11:42:02.012Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"Quanos SCHEMA ST4 on-premises contains a local privilege escalation vulnerability in the Client Update Service due to insecure deserialization in the .NET Remoting service. The service is configured with TypeFilterLevel.Full and is bound to local interfaces only through named pipes. A local authenticated attacker can connect to the local named pipe, obtain the .NET Remoting endpoint, and send specially crafted serialized objects. Successful exploitation results in arbitrary code execution in the context of the update process with NT AUTHORITY\\SYSTEM privileges. Network-only exploitation is not possible and local host access with an authenticated user session is required.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-11857 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-11857"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-11857"},{"category":"external","summary":"r.sec-consult.com","url":"https://r.sec-consult.com/quanos"}]},"product_tree":{"branches":[{"category":"vendor","name":"Quanos Solutions GmbH","branches":[{"category":"product_name","name":"SCHEMA ST4","branches":[{"category":"product_version","name":"SCHEMA ST4 on-premises, all versions","product":{"name":"Quanos Solutions GmbH SCHEMA ST4 SCHEMA ST4 on-premises, all versions","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:quanos_solutions_gmbh:schema_st4:schema_st4_on-premises\\,_all_versions:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-11857","title":"Insecure .NET Remoting deserialization in Quanos SCHEMA ST4 Client Update Service allows local privilege escalation","notes":[{"category":"description","text":"Quanos SCHEMA ST4 on-premises contains a local privilege escalation vulnerability in the Client Update Service due to insecure deserialization in the .NET Remoting service. The service is configured with TypeFilterLevel.Full and is bound to local interfaces only through named pipes. A local authenticated attacker can connect to the local named pipe, obtain the .NET Remoting endpoint, and send specially crafted serialized objects. Successful exploitation results in arbitrary code execution in the context of the update process with NT AUTHORITY\\SYSTEM privileges. Network-only exploitation is not possible and local host access with an authenticated user session is required.","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1"]},"scores":[{"cvss_v4":{"version":"4.0","vectorString":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","baseScore":8.4,"baseSeverity":"HIGH"},"products":["CSAFPID-1"]}],"remediations":[{"category":"none_available","details":"No fixed version is published yet. Monitor the upstream advisory.","product_ids":["CSAFPID-1"]}]}]}