CVE-2026-54776 json
CoreWCF: Unix Domain Socket PosixIdentity transport accepts connections that skip the security upgrade
published 4mo ago modified 4mo ago also EUVD-2026-42461 , GHSA-wjpq-6766-7f5j
- cvss
- 4.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 4%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- nuget CoreWCF.UnixDomainSocket 1.8.1, 1.9.1
- corewcf corewcf 1.8.1, 1.9.1
Is CVE-2026-54776 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 4mo ago
Exploit prediction
0.15% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-11).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 4.4 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
| GitHub | 3.1 | 4.4 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| nuget | CoreWCF.UnixDomainSocket | <1.8.1 >=1.9.0, <1.9.1 |
1.8.1 1.9.1 |
Affected products
- CoreWCF CoreWCF
Classification
- Weakness
-
- CWE-306 Missing Authentication for Critical Functionality
References
- github.com /CoreWCF/CoreWCF/commit/994431268e3362c0cd126450fe2a135c202551f3
- github.com /CoreWCF/CoreWCF/commit/9af16955e51a57348dafce0019e259a092ef7440
- github.com /CoreWCF/CoreWCF/commit/f2f1a05927a88b8a75fa0582fa8ed75eb891e463
-
github.com
/CoreWCF/CoreWCF/security/advisories/GHSA-wjpq-6766-7f5j
web
- github.com /CoreWCF/CoreWCF/releases/tag/v1.8.1
- github.com /CoreWCF/CoreWCF/releases/tag/v1.9.1
-
github.com
/CoreWCF/CoreWCF
package
Sources
- CVE List CVE-2026-54776
- GitHub Advisory GHSA-wjpq-6766-7f5j
- NVD CVE-2026-54776
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.