Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
CVE-2026-25551
Seagull Software BarTender Deserialization Privilege Escalation via .NET Remoting Service
AV AC AT PR UI VC VI VA CVSS EPSS %ile KEV
L L N L N H H H 8.5 .0036 27.2 —
AFFECTED
Product Versions Fixed
BarTender 2021 R1 – —
TIMELINE
Feb 2 Reserved by VulnCheck
Jun 4 Published (CNA: VulnCheck)
Sep 2 EXPLOIT PUBLISHED — CVE-2026-25551 (Seagull Software, LLC. BarTender 2021). Public exploit reference added.
Description
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. The vulnerability was corrected in BarTender 12.1, released on August 14, 2026. Users should upgrade to BarTender 12.1 or later.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
|---|
| February 2, 2026 | Reserved | Reserved by VulnCheck |
| June 4, 2026 | Published | Published (CNA: VulnCheck) |
| September 2, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-25551 (Seagull Software, LLC. BarTender 2021). Public exploit reference added. |
Affected
Affected products and packages — 1 row
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|
| Seagull Software, LLC. | BarTender 2021 | — | R1 | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-25551 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.
