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MEDIUM severity

GHSA-jc6x-rj79-w4mx — CoreWCF.Primitives

MEDIUM

GHSA-jc6x-rj79-w4mx is a medium-severity (CVSS 5.9) CWE-347 vulnerability in CoreWCF.Primitives. A fix is available for CoreWCF.Primitives — see the affected versions and patch details below.

CoreWCF: WS-Security signature substitution via document-wide Signature lookup

Also known asCVE-2026-54773
Published
Jun 19, 2026
Updated
Jun 19, 2026
Affected
2 pkgs
Patched
2 / 2
Exploits
None indexed
Exploitation data as of Sep 17, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-jc6x-rj79-w4mx.

EPSS Exploitation Probability

via FIRST.org ↗
0.4%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs31th percentile — riskier than 31% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

How urgent is this, really

GHSA-jc6x-rj79-w4mx plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 374,847 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Real-World Exposure

2 pkgs affected
.NETCoreWCF.Primitives.NETCoreWCF.Primitives

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.

Description

Impact

An unauthenticated remote attacker who can place a SOAP header lexically before wsse:Security can embed a ds:Signature of their choosing inside that header and cause the server to verify the attacker-supplied signature instead of the one carried in the security header.

Preconditions

Exploitation requires the endpoint be configured with an endorsing supporting token binding, and the attacker constructs a ds:Signature whose KeyInfo resolves through the receive-side token resolver to a key under the attacker’s control. Both are conditions outside the attacker’s direct control on a generic deployment.

Patches

Fixed in CoreWCF v1.8.1 and v1.9.1

Workarounds

Use a security token resolver that only accepts references to issuer-pinned X.509 chains (the default when expecting a static set of signing certificates).

Affected Packages

2 total 2 fixed
EcosystemPackageVulnerable rangeFix
.NETNuGetCoreWCF.Primitivesall versions1.8.1dotnet add package CoreWCF.Primitives --version 1.8.1
.NETNuGetCoreWCF.Primitives≥ 1.9.0&&< 1.9.11.9.1dotnet add package CoreWCF.Primitives --version 1.9.1

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for CoreWCF.Primitives, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update CoreWCF.Primitives to 1.8.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-jc6x-rj79-w4mx is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-jc6x-rj79-w4mx can be triaged on real exposure rather than presence alone.

Tailored to GHSA-jc6x-rj79-w4mx. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Impact An unauthenticated remote attacker who can place a SOAP header lexically before `wsse:Security` can embed a `ds:Signature` of their choosing inside that header and cause the server to verify the attacker-supplied signature instead of the one carried in the security header. #### Preconditions Exploitation requires the endpoint be configured with an endorsing supporting token binding, and the attacker constructs a `ds:Signature` whose `KeyInfo` resolves through the receive-side token resolver to a key under the attacker’s control. Both are conditions outside the attacker’s direct con
O3 Security · Impact-Aware SCA

Is GHSA-jc6x-rj79-w4mx in your dependencies?

O3 Security finds GHSA-jc6x-rj79-w4mx across NuGet dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works