CVE-2026-54775: CoreWCF Denial of Service Vulnerability

MODERATE
Advisory Identifier: GHSA-m744-jhq9-ppw6
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CVSS 6.5
CWE-755 CWE-754 CWE-248
Published
Advisory Summary

CVE-2026-54775 is a MODERATE (CVSS 6.5) denial of service vulnerability (CWE-755: Improper Handling of Exceptional Conditions) affecting CoreWCF libraries in the NuGet ecosystem. The issue involves kafka consume pump halts permanently on a kafka tombstone (null-value record), causing persistent endpoint denial of service.. Remediation is available by upgrading affected packages to version 1.8.1, 1.9.1.

CVE-2026-54775 at a Glance

CVE Identifier CVE-2026-54775
GHSA Identifier GHSA-m744-jhq9-ppw6
Severity MODERATE
CVSS v3.1 Base Score 6.5
CWE Classification CWE-755: Improper Handling of Exceptional Conditions
Affected Product CoreWCF
Package Ecosystem NuGet
Published Date
Last Updated

Security Impact

CVSS: 6.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-54775

To remediate this vulnerability, upgrade all affected CoreWCF dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

CoreWCF.Kafka fixed: 1.8.1 
Upgrade CoreWCF.Kafka to 1.8.1
CoreWCF.Kafka fixed: 1.9.1 
Upgrade CoreWCF.Kafka to 1.9.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for CoreWCF.Kafka

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-54775, inspect your project dependencies for CoreWCF:

inspect dependencies for CoreWCF.Kafka

Analyze the terminal output to locate any version of CoreWCF in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.8.1), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-755: Improper Handling of Exceptional Conditions, where the product does not handle or incorrectly handles an exceptional condition. In CoreWCF, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact A CoreWCF service is running and listening on a Kafka topic receiving a null-value record will stop processing new records from that topic. #### Preconditions The attacker has produce/write permission on a topic that CoreWCF is consuming from. If the broker permits anonymous publishes, no authentication is required. ### Patches Fixed in CoreWCF v1.8.1 and v1.9.1 ### Workarounds Only allow authenticated writes to a topic

CVE-2026-54775 Affected CoreWCF Versions

2 component(s)
Fixed Versions:
1.8.11.9.1
Product / Package Ecosystem Affected Versions Fixed Version
CoreWCF.Kafka
nuget/CoreWCF.Kafka
NuGet
< 1.8.1
1.8.1
CoreWCF.Kafka
nuget/CoreWCF.Kafka
NuGet
≥ 1.9.0
< 1.9.1
1.9.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-m744-jhq9-ppw6
CoreWCF Source Repository REPOSITORY
https://github.com/CoreWCF/CoreWCF

Frequently Asked Questions

What is CVE-2026-54775?
CVE-2026-54775 is a security vulnerability in CoreWCF involving Kafka consume pump halts permanently on a Kafka tombstone (null-value record), causing persistent endpoint denial of service. under CWE-755: Improper Handling of Exceptional Conditions.
Which CoreWCF versions are affected?
Affected versions include releases prior to 1.8.1, 1.9.1 across affected packages: CoreWCF.Kafka.
What version fixes CVE-2026-54775?
Upgrading to 1.8.1, 1.9.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is CoreWCF.Kafka affected?
Yes, CoreWCF.Kafka is affected in releases prior to 1.8.1, 1.9.1. Upgrade your dependency to 1.8.1, 1.9.1 or later.
What is the CVSS score of CVE-2026-54775?
CVE-2026-54775 has a CVSS v3.1 base score of 6.5 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-54775?
CVE-2026-54775 is classified under CWE-755: Improper Handling of Exceptional Conditions (The product does not handle or incorrectly handles an exceptional condition.).
How can I check NuGet dependencies for CVE-2026-54775?
Run the dependency tree command: 'inspect dependencies for CoreWCF.Kafka'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-m744-jhq9-ppw6",
  "modified" : "2026-06-19T20:46:49Z",
  "published" : "2026-06-19T20:46:49Z",
  "aliases" : [ "CVE-2026-54775" ],
  "summary" : "CoreWCF: Kafka consume pump halts permanently on a Kafka tombstone (null-value record), causing persistent endpoint denial of service.",
  "details" : "### Impact\nA CoreWCF service is running and listening on a Kafka topic receiving a null-value record will stop processing new records from that topic.\n\n#### Preconditions\nThe attacker has produce/write permission on a topic that CoreWCF is consuming from. If the broker permits anonymous publishes, no authentication is required. \n\n### Patches\nFixed in CoreWCF v1.8.1 and v1.9.1\n\n### Workarounds\nOnly allow authenticated writes to a topic",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "CoreWCF.Kafka"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.8.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "CoreWCF.Kafka"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.9.0"
      }, {
        "fixed" : "1.9.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-m744-jhq9-ppw6"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/CoreWCF/CoreWCF"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-248", "CWE-754", "CWE-755" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-19T20:46:49Z",
    "nvd_published_at" : null
  }
}