Critical Authentication exploit reference

CVE-2026-25550 — Seagull Software BarTender Unauthenticated RCE via .NET Remoting Service

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.

Published Jun 4, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: VulnCheck

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 1.4% (30-day exploitation probability)+11
Technical severity (critical)+10
Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

1.42%

ahead of 72% of scored CVEs · Oct 15, 2026

Affects

Seagull Software, LLC.

BarTender 2010 and 2 more

CVSS base

9.8

Critical · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

Yes

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Seagull Software, LLC. BarTender 2010, Seagull Software, LLC. BarTender 2016, Seagull Software, LLC. BarTender 2019).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes matching the vulnerability class (authentication), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Seagull Software, LLC.	BarTender 2010	≤ 10.1 R4	Vulnerable	CVE Program (cve.org) e CISA ADP
Seagull Software, LLC.	BarTender 2016	≤ R9	Vulnerable	CVE Program (cve.org) e CISA ADP
Seagull Software, LLC.	BarTender 2019	≤ R10	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
9.3	CVSS 4.0	Critical	—	—	disclosure@vulncheck.com via NIST National Vulnerability Database
9.3	CVSS 4.0	Critical	—	—	VulnCheck via CVE Program (cve.org) e CISA ADP
9.8	CVSS 3.1	Critical	3.9	5.9	disclosure@vulncheck.com via NIST National Vulnerability Database
9.8	CVSS 3.1	Critical	—	—	VulnCheck via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: disclosure@vulncheck.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-306 · Missing Authentication for Critical Function

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 1.42%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Review authentication logs: logins without MFA, anomalous sessions and recently created accounts.

web/proxy/WAF logsnetwork IDS/IPSauthentication logs

Timeline

What happened to this CVE, newest first.

2026
Affected products added · seagull software, llc./bartender 2010, seagull software, llc./bartender 2016, seagull software, llc./bartender 2019
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
CVSS changed · 9.8
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Awaiting Analysis
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Jun 4, 2026 · VulnCheck

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

4 on the record

trust.seagullsoftware.com/
vendor-advisory, patch, NIST National Vulnerability Database
www.vulncheck.com/advisories/seagull-software-bartender-unauthenticated-rce-via-net-rem
third-party-advisory, NIST National Vulnerability Database
portal.seagullscientific.com/downloads/bartender
product, NIST National Vulnerability Database
gist.github.com/VAMorales/dde5b1c0415a8505ccd6fafdb095a618
technical-description, exploit, NIST National Vulnerability Database

Elsewhere on this site

Seagull Software, LLC.
every CVE for this vendor

Authentication
same class

CWE-306
other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-25550 is "Seagull Software BarTender Unauthenticated RCE via .NET Remoting Service", rated Critical. It affects BarTender 2010 (Seagull Software, LLC.); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.8 describes technical severity. EPSS 1.42% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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