# CVE-2026-54780

## Summary

- **CVE ID:** CVE-2026-54780
- **Severity:** LOW
- **CVSS Score:** 3.7 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N)
- **CWE:** CWE-327, CWE-757
- **Published:** Jul 8, 2026
- **Last Modified:** Jul 10, 2026

## 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, the CoreWCF WS-Security 1.0 receive pipeline validates ds:SignedInfo SignatureMethod against the configured SecurityAlgorithmSuite but does not validate each ds:Reference DigestMethod, allowing a sender to use a rejected digest algorithm such as SHA-1 while the message is still accepted. This issue is fixed in versions 1.8.1 and 1.9.1.

## Affected Products

- CoreWCF — CoreWCF (>= 1.9.0, < 1.9.1)
- CoreWCF — CoreWCF (< 1.8.1)

## References

- [CNA](https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-4v55-cpmv-3vcm)
- [CNA](https://github.com/CoreWCF/CoreWCF/commit/58742312117cc671e6e9c694c2f5f9f669c17136)
- [CNA](https://github.com/CoreWCF/CoreWCF/commit/9104e581cff3d047ace5e179bfae86807a44be1f)
- [CNA](https://github.com/CoreWCF/CoreWCF/commit/fea67b2cd73a5a85115c325d504303ec7382e133)
- [CNA](https://github.com/CoreWCF/CoreWCF/releases/tag/v1.8.1)
- [CNA](https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.24%
- **EPSS Percentile:** 14.7

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._