Answer in brief
CVE-2026-54773 records a Medium severity (CVSS 5.9) vulnerability in CoreWCF: WS-Security signature substitution via document-wide Signature lookup. The current sources do not mark it as known exploited. The current feed maps CoreWCF/CoreWCF (generic), CoreWCF.Primitives (nuget), CoreWCF.Primitives (nuget). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.9. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps CoreWCF/CoreWCF (generic), CoreWCF.Primitives (nuget), CoreWCF.Primitives (nuget). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| CoreWCF/CoreWCFgeneric | >= 1.9.0, < 1.9.1 || < 1.8.1 | Not reported |
| CoreWCF.Primitivesnuget | <1.8.1 | 1.8.1 |
| CoreWCF.Primitivesnuget | >=1.9.0,<1.9.1 | 1.9.1 |
Published upstream
Jul 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 10, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 19, 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, CoreWCF WS-Security signature verification performs a document-wide ds:Signature lookup, allowing an unauthenticated remote attacker to place a SOAP header before wsse:Security and cause WSSecurityOneDotZeroReceiveSecurityHeader to verify an attacker-supplied signature instead of the security header signature. This issue is fixed in versions 1.8.1 and 1.9.1.
Quoted source text, attributed separately from HOL analysis.