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Vulnerability · Published Jul 8, 2026 · Assigned by GitHub_M

CVE-2026-54776CoreWCF: Unix Domain Socket PosixIdentity transport accepts connections that skip the security upgrade

Medium 4.4

In plain English

A medium-severity missing authentication in CoreWCF from CoreWCF. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 4% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)4.4Medium
Exploit odds (30 days)0.2%top 95.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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, a CoreWCF service hosted on Unix Domain Sockets with PosixIdentity client credentials can accept connections that skip the application/unixposix stream upgrade before dispatching messages, bypassing framing-layer identity checks in UnixPosixIdentitySecurityUpgradeProvider. This issue is fixed in versions 1.8.1 and 1.9.1.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
NuGetcorewcf.unixdomainsocket1.8.1GHSA-wjpq-6766-7f5j
NuGetcorewcf.unixdomainsocket1.9.1GHSA-wjpq-6766-7f5j

Affected products (as reported)

VendorProductVersions
CoreWCF CoreWCF >= 1.9.0, < 1.9.1< 1.8.1

Weakness: CWE-306 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

References