CVE-2026-54775 CoreWCF: Kafka consume pump halts permanently on a Kafka tombstone (null-value record), causing persistent endpoint denial of service.
An attacker with produce permissions can cause a permanent denial of service in CoreWCF services by sending a null-value Kafka record.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-54775?
CVE-2026-54775 is a medium-severity denial of service vulnerability in CoreWCF, published on 8 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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, a CoreWCF service listening on a Kafka topic stops processing new records from that topic when KafkaTransportPump receives a null-value tombstone record, causing a persistent endpoint denial of service for attackers with produce permission. This issue is fixed in versions 1.8.1 and 1.9.1.
Which versions are affected by CVE-2026-54775?
4 open source packages ship an affected version, including CoreWCF.Kafka.
| Package | Affected | Fixed in |
|---|---|---|
CoreWCF.Kafka NuGet | All versions | 1.8.1 |
CoreWCF.Kafka NuGet | All versions | 1.8.1 |
CoreWCF.Kafka NuGet | From 1.9.0 | 1.9.1 |
CoreWCF.Kafka NuGet | From 1.9.0 | 1.9.1 |
How do I fix CVE-2026-54775?
Upgrade CoreWCF.Kafka to a fixed version for your release line: 1.8.1 or 1.9.1.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-54775 being exploited?
There is no known exploitation of CVE-2026-54775 in the wild and no public exploit code.
Sources
Also known as GHSA-m744-jhq9-ppw6.