CVE-2026-25551 HIGH

CVE-2026-25551: Seagull Software BarTender Deserialization Privilege Escalation via .NET Remoting Service

Vendor Seagull Software, Llc.
Product BarTender 2021
Weakness CWE-502 · Unsafe deserialization
Published June 4, 2026
Last update June 8, 2026
View on NVD All CVEs

CVSS base score

8.5/10
Attack vector Local
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality —
Integrity —

CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

What the vulnerability does

01Description

Seagull Software BarTender 2021 R1 through 12.0.1 contains an insecure deserialization vulnerability that allows low-privileged local users to escalate privileges. The DataServiceSingleton .NET Remoting endpoint is bound to localhost on TCP port 7375 via BtSystem.Service.exe, limiting the attack surface to local access only. The endpoint is configured with BinaryServerFormatterSinkProvider and TypeFilterLevel set to Full. A low-privileged local attacker can send YSoSerial.NET-generated BinaryFormatter payloads to the localhost-bound endpoint to achieve code execution as NT AUTHORITY\\SYSTEM.

Key dates

02Disclosure timeline

June 4, 2026 CVE published
June 8, 2026 Record updated