CVE-2026-25550 Seagull Software BarTender Unauthenticated RCE via .NET Remoting Service
Unauthenticated attackers can achieve remote code execution and privilege escalation via insecure .NET Remoting deserialization in BarTender.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-25550?
CVE-2026-25550 is a critical unsafe deserialization vulnerability in Seagull Software, LLC. BarTender 2010, published on 4 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Seagull Software BarTender 2010, 2016, and 2019 contain an unauthenticated remote code execution vulnerability in the .NET Remoting service exposed on TCP port 7375 via BtSystem.Service.exe. The service registers an unauthenticated singleton endpoint — BarTenderSystem for BarTender 2016 <= R9, and DataServiceSingleton for BarTender 2019 <= R10 — configured with BinaryServerFormatterSinkProvider and TypeFilterLevel set to Full. An unauthenticated remote attacker can exploit .NET Remoting object unmarshalling to read or write arbitrary files on the server using the .NET WebClient class, or coerce NTLMv2 authentication by supplying a UNC path to an attacker-controlled server, enabling sensitive credential disclosure, remote code execution, or lateral movement depending on service account privileges and network environment. The service runs in the context of NT AUTHORITY\\SYSTEM. This vulnerability is corrected in BarTender 12.0.1. Users of affected releases should upgrade to BarTender 12.0.1 or later.
Which versions are affected by CVE-2026-25550?
How do I fix CVE-2026-25550?
No fix has been published for CVE-2026-25550 yet. Limit exposure of the affected software until one is available.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-25550 being exploited?
There is no known exploitation of CVE-2026-25550 in the wild and no public exploit code.
Sources
Also known as GHSA-2q9g-666g-vcp9.