PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-54773 CoreWCF CVE debrief

A vulnerability in CoreWCF, a port of the service side of Windows Communication Foundation (WCF) to .NET Core, allows an unauthenticated remote attacker to 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. The vulnerability affects users of CoreWCF versions prior to 1.8.1 and 1.9.1, who should update to a fixed version to prevent potential attacks. The vulnerability has a CVSS score of 5.9 and a severity of MEDIUM.

Vendor
CoreWCF
Product
Unknown
CVSS
MEDIUM 5.9
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-08
Original CVE updated
2026-07-10
Advisory published
2026-07-08
Advisory updated
2026-07-10

Who should care

Users of CoreWCF versions prior to 1.8.1 and 1.9.1 should update to a fixed version to prevent potential attacks. This includes operators, platform administrators, vulnerability management teams, and security teams who need to review and update affected systems.

Technical summary

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 can be mitigated by updating to CoreWCF version 1.8.1 or 1.9.1. Affected systems should be reviewed and updated to prevent potential attacks.

Defensive priority

Medium

Recommended defensive actions

  • Update to CoreWCF version 1.8.1 or 1.9.1
  • Review and update affected systems
  • Monitor for potential attacks
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record was published on 2026-07-08T23:16:54.960Z and was last modified on 2026-07-10T15:16:41.373Z. The source of this information is nvd_modified. Evidence limits suggest that further verification is needed to confirm affected scope and severity. Defenders should verify the official advisory or CVE record to validate affected systems and plan for updates or mitigations.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-54773 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-54773

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-54773 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-54773

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.