CVE-2026-54783
CoreWCF: XML Signature Wrapping in WS-Security endorsing/supporting signature verification allows replay of captured signed messages
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
CoreWCF: XML Signature Wrapping in WS-Security endorsing/supporting signature verification allows replay of captured signed messages
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.
- Record
CVE-2026-54783- CVSS 3.1
- 7.4 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-294, CWE-345, CWE-347
- Updated
- 2026-11-02
EUVDEUVD-2026-42469
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.
- Record
EUVD-2026-42469- CVSS 3.1
- 7.4 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-gqv6-pwcg-87r8
CoreWCF: XML Signature Wrapping in WS-Security endorsing/supporting signature verification allows replay of captured signed messages
Impact
The attacker, with one captured signed SOAP envelope from a victim and no other privileges, can invoke arbitrary operations on the service as the victim principal for the lifetime of the captured signing key. There is no rate limit on replays. The DetectReplays setting on transport-security bindings does not mitigate the issue because the attack does not reuse the original timestamp — the fresh timestamp in the wsse:Security header is what the replay-detection logic inspects.
Patches
Fixed in CoreWCF v1.8.1 and v1.9.1
Workarounds
Ensure communication is protected by SSL/TLS to prevent capturing of signed SOAP envelope.
- Record
GHSA-gqv6-pwcg-87r8- CVSS 3.1
- 7.4 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-294, CWE-345, CWE-347
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-54783- CVSS 3.1
- 7.4 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-294, CWE-345, CWE-347
- Updated
- 2026-11-02
OSV
CoreWCF: XML Signature Wrapping in WS-Security endorsing/supporting signature verification allows replay of captured signed messages
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.
- Record
CVE-2026-54783- CVSS 3.1
- 7.4 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-294, CWE-345, CWE-347
- Updated
- 2026-11-02
OSVGHSA-gqv6-pwcg-87r8
CoreWCF: XML Signature Wrapping in WS-Security endorsing/supporting signature verification allows replay of captured signed messages
Impact
The attacker, with one captured signed SOAP envelope from a victim and no other privileges, can invoke arbitrary operations on the service as the victim principal for the lifetime of the captured signing key. There is no rate limit on replays. The DetectReplays setting on transport-security bindings does not mitigate the issue because the attack does not reuse the original timestamp — the fresh timestamp in the wsse:Security header is what the replay-detection logic inspects.
Patches
Fixed in CoreWCF v1.8.1 and v1.9.1
Workarounds
Ensure communication is protected by SSL/TLS to prevent capturing of signed SOAP envelope.
- Record
GHSA-gqv6-pwcg-87r8- CVSS 3.1
- 7.4 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-294, CWE-345, CWE-347
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
CoreWCF.PrimitivesNuGet |
before 1.8.1 | 1.8.1 |
CoreWCF.PrimitivesNuGet |
1.9.0 up to 1.9.1 | 1.9.1 |
CoreWCF.PrimitivesNuGet |
before 1.8.1, plus listed versions 0.1.00.1.0-preview0.1.0-preview-20.2.00.2.1 Show 27 moreShow less0.3.00.3.10.3.20.4.01.0.01.0.0-preview11.0.0-preview21.0.11.0.21.1.01.1.11.2.01.2.11.3.01.3.11.3.21.4.01.4.0-preview11.4.11.4.21.5.01.5.0-preview11.5.11.5.21.6.01.7.01.8.0 |
1.8.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-54783 is a high vulnerability (CVSS 7.4) in Corewcf, published June 19, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.19%, the 9th percentile. Fixed in CoreWCF.Primitives 1.8.1.
References
github.com/CoreWCF/CoreWCF/security/advisories/GHSA-gqv6-pwcg-87r8