CoreWCF: WS-Security signature substitution via document-wide Signature lookup
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-347.
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, 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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| CoreWCF | CoreWCF | 1.9.0 to before 1.9.1; before 1.8.1 | 1.9.1, 1.8.1 | Patch available | CNA |
| — | CoreWCF.Primitives (NuGet) | before 1.8.1 | 1.8.1 | Patch available | GHSA-jc6x-rj79-w4mx |
| — | CoreWCF.Primitives (NuGet) | 1.9.0 to before 1.9.1 | 1.9.1 | Patch available | GHSA-jc6x-rj79-w4mx |
- CoreWCF VendorCoreWCF Affected 1.9.0 to before 1.9.1; before 1.8.1 Fixed in 1.9.1, 1.8.1 Patch available CNA
- CoreWCF.Primitives (NuGet) Vendor— Affected before 1.8.1 Fixed in 1.8.1 Patch available GHSA-jc6x-rj79-w4mx
- CoreWCF.Primitives (NuGet) Vendor— Affected 1.9.0 to before 1.9.1 Fixed in 1.9.1 Patch available GHSA-jc6x-rj79-w4mx
Remediation
- Fix · CNA CoreWCF (CoreWCF) Fixed in 1.9.1, 1.8.1
- Fix · GHSA-jc6x-rj79-w4mx CoreWCF.Primitives (NuGet) Fixed in 1.8.1 Advisory →
- Fix · GHSA-jc6x-rj79-w4mx CoreWCF.Primitives (NuGet) Fixed in 1.9.1 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-54773
- 2026-10-03 Alias added: GHSA-jc6x-rj79-w4mx
References
Other 7
- https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-jc6x-rj79-w4mx
- https://github.com/CoreWCF/CoreWCF/commit/0589692d4b9a41d21b34ac48281e95f6df7f4ce5
- https://github.com/CoreWCF/CoreWCF/commit/30aef805270976c42477e3f2a05f4e563d86e247
- https://github.com/CoreWCF/CoreWCF/commit/4618f24165ad018ad3ed2636bf8c3bc87d2a3be2
- https://github.com/CoreWCF/CoreWCF/releases/tag/v1.8.1
- https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1
- https://github.com/CoreWCF/CoreWCF
More CoreWCF vulnerabilities
- TI-2026-39588 CoreWCF: Authentication bypass in CoreWCF SAML 1.1 / 2.0 token signature validation CVSS 3.1CRITICAL 10.0
- TI-2026-39578 CoreWCF: Pre-authentication infinite-loop CPU exhaustion in CoreWCF net.tcp / net.pipe / net.uds framing handshake CVSS 3.1HIGH 7.5
- TI-2024-18811 CoreWCF NetFraming based services can leave connections open when they should be closed CVSS 3.1HIGH 7.5
- TI-2026-39590 CoreWCF: SPNEGO SecurityContextToken proof key wrapped without confidentiality CVSS 3.1HIGH 7.4
- TI-2026-39589 Authentication bypass by capture-replay in CoreWCF CVSS 3.1HIGH 7.4
- TI-2026-39587 CoreWCF: SAML SubjectConfirmation methods and holder-of-key proof keys are not enforced CVSS 3.1HIGH 7.4
Sources
- CVE-2026-54773 · CVE Program
- CVE-2026-54773 · NVD
- FIRST EPSS
- GHSA-jc6x-rj79-w4mx · GitHub Advisory Database · CC BY 4.0
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