SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-54783

Prior to 1.8.1 and 1.9.1, CoreWCF WS-Security endorsing and supporting signature verification does not ensure the selected ds:Signature covers the expected Security header target, allowing an attacker with one captured signed SOAP envelope to replay…

HIGH 7.4EPSS 0.19%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.19%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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, CoreWCF WS-Security endorsing and supporting signature verification does not ensure the selected ds:Signature covers the expected Security header target, allowing an attacker with one captured signed SOAP envelope to replay arbitrary service operations as the victim principal. This issue is fixed in versions 1.8.1 and 1.9.1.

CVSS 3.1
7.4 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS
0.19% probability · 9th percentile
CISA KEV
Not listed
Weakness
CWE-294, CWE-345, CWE-347
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.