# CVE-2026-54775 — CoreWCF

> As of 2026-07-09, CVE-2026-54775 is a MEDIUM-severity vulnerability in CoreWCF, CVSS v3.1 6.5, EPSS 0.3% (25.6th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-54775 as of 2026-07-09; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-07-09

## What is CVE-2026-54775?

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.

The record classifies CVE-2026-54775 under weakness classes [CWE-248](https://cwe.mitre.org/data/definitions/248.html), [CWE-754](https://intel.threadlinqs.com/cwe/CWE-754), [CWE-755](https://cwe.mitre.org/data/definitions/755.html). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction, and has high impact on availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 89 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 6.5 — MEDIUM (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **EPSS (FIRST):** 0.3% probability of exploitation in the next 30 days, higher than 25.6% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 4.3/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-07-08, last modified 2026-07-09

## Is CVE-2026-54775 being exploited?

It currently carries a trending score of 35 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [CoreWCF](https://intel.threadlinqs.com/vendors/corewcf): CoreWCF

## How to fix CVE-2026-54775

No vendor patch reference has been recorded for CVE-2026-54775 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-54775

No threat campaign in the Threadlinqs corpus currently references CVE-2026-54775, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, NVD, FIRST EPSS. Last verified by Threadlinqs on 2026-07-12. This product uses the NVD API but is not endorsed or certified by the NVD.

**Vendor advisory and patch**

- [github.com](https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-m744-jhq9-ppw6)

**Other references**

- [github.com](https://github.com/CoreWCF/CoreWCF/commit/1a229d0d14a07766302f7d14c866889f04a3a624)
- [github.com (6d7431ebc0ebe6521ea6d0dbea8982bac3d2bc98)](https://github.com/CoreWCF/CoreWCF/commit/6d7431ebc0ebe6521ea6d0dbea8982bac3d2bc98)
- [github.com (8f95f3ac3c929409e830b5c5659683ef9f6ea6b0)](https://github.com/CoreWCF/CoreWCF/commit/8f95f3ac3c929409e830b5c5659683ef9f6ea6b0)
- [github.com (v1.8)](https://github.com/CoreWCF/CoreWCF/releases/tag/v1.8.1)
- [github.com (v1.9)](https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-54775
Full detection coverage and IOCs for threats exploiting CVE-2026-54775 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp