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.NET
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Not in CISA KEV
HIGH severity

GHSA-2288-8h3r-cqgg

HIGH

GHSA-2288-8h3r-cqgg is a high-severity (CVSS 7.4) CWE-311 vulnerability in CoreWCF.Primitives. O3 Security confirms whether GHSA-2288-8h3r-cqgg is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

CoreWCF: SPNEGO SecurityContextToken proof key wrapped without confidentiality

Also known asCVE-2026-54784
Published
Jun 19, 2026
Updated
Jun 19, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Aug 21, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • A successful exploit gives an attacker total control of the affected component, not partial access.
  • 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-2288-8h3r-cqgg.

EPSS Exploitation Probability

via FIRST.org ↗
0.2%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs7th percentile — riskier than 7% of all scored CVEsHighest risk
0.00%0.22%0.45%0.68%0.2%0.2%Aug 26Aug 26

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-2288-8h3r-cqgg 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 363,588 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

1 pkg affected
.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

When the proof key recovered from the RSTR can be observed by a party that is not the legitimate client, that party can impersonate the authenticated Windows principal for the lifetime of the SCT (default ~10 hours) and decrypt or forge any subsequent WS‑SecureConversation traffic that uses keys derived from the SCT.

Preconditions

Using security mode TransportWithMessageCredential with client credential type Windows, along with session establishment (which triggers use of WS-SecureConversation).

Patches

Fixed in CoreWCF v1.9.1

Workarounds

Ensure communication is protected by SSL/TLS to prevent capturing of SCT negotiation handshake.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
.NETNuGetCoreWCF.Primitives1.9.0&&< 1.9.11.9.1

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. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update CoreWCF.Primitives to 1.9.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-2288-8h3r-cqgg 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 pinpoints whether GHSA-2288-8h3r-cqgg is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-2288-8h3r-cqgg. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Impact When the proof key recovered from the RSTR can be observed by a party that is not the legitimate client, that party can impersonate the authenticated Windows principal for the lifetime of the SCT (default ~10 hours) and decrypt or forge any subsequent WS‑SecureConversation traffic that uses keys derived from the SCT. #### Preconditions Using security mode TransportWithMessageCredential with client credential type Windows, along with session establishment (which triggers use of WS-SecureConversation). ### Patches Fixed in CoreWCF v1.9.1 ### Workarounds Ensure communication is prot
O3 Security · Impact-Aware SCA

Is GHSA-2288-8h3r-cqgg in your dependencies?

O3 detects GHSA-2288-8h3r-cqgg across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

GHSA-2288-8h3r-cqgg: CoreWCF.Primitives… | O3 Security