CVE-2026-54784 | BDVDB-2026-346245 Detail

CoreWCFCoreWCF

Description#

CoreWCF is a port of the service side of Windows Communication Foundation (WCF) to .NET Core. In version 1.9.0, CoreWCF SPNEGO SecurityContextToken negotiation can expose the proof key recovered from the RSTR when TransportWithMessageCredential with Windows client credentials and session establishment are used, allowing an observer to impersonate the authenticated Windows principal and decrypt or forge WS-SecureConversation traffic. This issue is fixed in version 1.9.1.

Impact#

Per CVSS v3.1: confidentiality impact high, integrity impact high, availability impact none. Attack vector: network.

Weaknesses#

CWE-311 Missing Encryption of Sensitive Data
CWE-523 Unprotected Transport of Credentials

References#

Exploit#

No public exploit known

History#

Version 12026-07-08Record published in the CVE List.
Version 22026-07-10Most recent update recorded in the CVE List.

Published

Published: 2026-07-08
Last modified: 2026-07-10

Vendor information

Vendor: CoreWCF
Product: CoreWCF

All CoreWCF vulnerabilities

Score

7.4 High

EPSS

less than 1%, Very Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 19.7.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Not classified

Action

No specific action is recorded in the source data. Check the references for vendor guidance.

Affected Systems

Vulnerable
>= 1.9.0, < 1.9.1
Fixed
Not stated

Scoring System

CVSS v4.0

Not available

CVSS v3.1

7.4 High

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Metric breakdown
Attack Vector	Network
Attack Complexity	High
Privileges Required	None
User Interaction	None
Scope	Unchanged
Confidentiality	High
Integrity	High
Availability	None

CVSS v3.0

Not available

CVSS v2

Not available

Source: CVE List v5 (record); CISA KEV (kev, action); FIRST EPSS (epss).