What’s Vulnerable › Vulnerabilities

CVE-2026-54777: CoreWCF NetNamedPipe transport accepts attach to a pre-existing named pipe instance

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-08 · updated 2026-07-10
• Weakness: CWE-367

Description

CoreWCF is a port of the service side of Windows Communication Foundation (WCF) to .NET Core. Prior to 1.8.1 and 1.9.1, CoreWCF NetNamedPipe transport accepts attachment to a pre-existing named pipe instance, allowing local interception of NetNamedPipe traffic when an attacker races NamedPipeListener startup between shared memory GUID publication and service named pipe creation. This issue is fixed in versions 1.8.1 and 1.9.1.

Affected products

• CoreWCF: from 1.9.0, < 1.9.1; before 1.8.1

References

• https://github.com/CoreWCF/CoreWCF/commit/8ed9c780c7c6fb22fa215c5771dee0c1e49596b7
• https://github.com/CoreWCF/CoreWCF/commit/e7d225394fd429900dcbc445dcdd53b94e964077
• https://github.com/CoreWCF/CoreWCF/releases/tag/v1.8.1
• https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1
• https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-6jj2-4q5c-x8g6

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