Medium 4.4Published Jul 8, 2026

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

Updated under an hour ago (Oct 27, 2026, 7:40 PM ET)

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No exploitation reported and no EPSS estimate yet.

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Every CVE for CoreWCF

Exploited in the last 30 days

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.

CVSS: 4.4 MEDIUM (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Weakness (CWE): CWE-306
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Jul 9, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

CoreWCF CoreWCF corewcf:corewcf (from the name)	from 1.9.0, < 1.9.1; before 1.8.1	CNA record

References

References

https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-wjpq-6766-7f5j	x-refsource-confirm
https://github.com/CoreWCF/CoreWCF/commit/994431268e3362c0cd126450fe2a135c202551f3	x-refsource-misc
https://github.com/CoreWCF/CoreWCF/commit/9af16955e51a57348dafce0019e259a092ef7440	x-refsource-misc
https://github.com/CoreWCF/CoreWCF/commit/f2f1a05927a88b8a75fa0582fa8ed75eb891e463	x-refsource-misc
https://github.com/CoreWCF/CoreWCF/releases/tag/v1.8.1	x-refsource-misc
https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1	x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.