CoreWCF: Pre-authentication infinite-loop CPU exhaustion in CoreWCF net.tcp / net.pipe / net.uds framing handshake
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-400.
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, an unauthenticated remote attacker that can reach a NetTcpBinding, NetNamedPipeBinding, or UnixDomainSocketBinding endpoint can trigger premature EOF handling in the CoreWCF net.tcp, net.pipe, or net.uds framing handshake and pin one server thread-pool worker at full CPU per connection. 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
- Yes
- 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.NetFramingBase (NuGet) | before 1.8.1 | 1.8.1 | Patch available | GHSA-p86g-xrr2-pf7c |
| — | CoreWCF.NetFramingBase (NuGet) | 1.9.0 to before 1.9.1 | 1.9.1 | Patch available | GHSA-p86g-xrr2-pf7c |
- 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.NetFramingBase (NuGet) Vendor— Affected before 1.8.1 Fixed in 1.8.1 Patch available GHSA-p86g-xrr2-pf7c
- CoreWCF.NetFramingBase (NuGet) Vendor— Affected 1.9.0 to before 1.9.1 Fixed in 1.9.1 Patch available GHSA-p86g-xrr2-pf7c
Remediation
- Fix · CNA CoreWCF (CoreWCF) Fixed in 1.9.1, 1.8.1
- Fix · GHSA-p86g-xrr2-pf7c CoreWCF.NetFramingBase (NuGet) Fixed in 1.8.1 Advisory →
- Fix · GHSA-p86g-xrr2-pf7c CoreWCF.NetFramingBase (NuGet) Fixed in 1.9.1 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-54772
- 2026-10-03 Alias added: GHSA-p86g-xrr2-pf7c
References
Other 7
- https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-p86g-xrr2-pf7c
- https://github.com/CoreWCF/CoreWCF/commit/03ddbced349931a2da6c0efcdf745c0722eff77c
- https://github.com/CoreWCF/CoreWCF/commit/7ddd966d6e58564a32ab30c825dd693b45a34a55
- https://github.com/CoreWCF/CoreWCF/commit/c4212988cd6fd472783d0413426eeac61044097a
- 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-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
- TI-2026-39580 CoreWCF: SamlSerializer skips SignatureValue verification when SAML signing token is not an X.509 certificate CVSS 3.1HIGH 7.4
Sources
- CVE-2026-54772 · CVE Program
- CVE-2026-54772 · NVD
- FIRST EPSS
- GHSA-p86g-xrr2-pf7c · GitHub Advisory Database · CC BY 4.0
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