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Fencer Vulns
critical 9.8

CVE-2026-25550 json

Seagull Software BarTender Unauthenticated RCE via .NET Remoting Service

published 2026-06-04 5 mo ago modified 2026-09-16 53 d ago also EUVD-2026-34304

cvss
9.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 59%
public exploits
0
none known

Summary

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.

Patch / fix

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
total
Assessed
5 mo ago

Exploit prediction

0.88% chance of exploitation in the next 30 days, higher than 59% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • gist.github.com https://gist.github.com/VAMorales/dde5b1c0415a8505ccd6fafdb095a618 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA 4.0 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • Seagull Software, LLC. BarTender 2010
  • Seagull Software, LLC. BarTender 2016
  • Seagull Software, LLC. BarTender 2019

Classification

Weakness
  • CWE-306 Missing Authentication for Critical Functionality
  • CWE-502 Deserialization of Untrusted Data

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.