PT-2026-46298 · Seagull · Bartender 2021

Vulncheck · Published 2026-06-04 · Updated 2026-06-04 · CVE-2026-25551

NVD

CVSS v3.1

7.8

High

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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 AUTHORITYSYSTEM.

Exploit

Fix

Deserialization of Untrusted Data

Weakness Enumeration

CWE-502

Related Identifiers

CVE-2026-25551

Affected Products

Bartender 2021

References · 4

• 🔥 https://gist.github.com/VAMorales/dde5b1c0415a8505ccd6fafdb095a618 · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2026-25551 · Security Note
• https://portal.seagullscientific.com/downloads/bartender · Note
• https://vulncheck.com/advisories/seagull-software-bartender-deserialization-privilege-escalation-via-net-remoting-service · Note