CVE-2026-54776 PUBLISHED

CoreWCF: Unix Domain Socket PosixIdentity transport accepts connections that skip the security upgrade

Assigner: GitHub_M
Reserved: 15.06.2026 Published: 08.07.2026 Updated: 09.07.2026

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.

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
CVSS Score: 4.4

Attack Vector	Local	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	Low
Privileges Required	Low	Integrity Impact	Low
User Interaction	None	Availability Impact	None

CVSS 3.1

Product Status

Vendor	CoreWCF
Product	CoreWCF
Versions	Version >= 1.9.0, < 1.9.1 is affected Version < 1.8.1 is affected

References

Problem Types

CWE-306: Missing Authentication for Critical Function CWE