How severe is GHSA-6jj2-4q5c-x8g6?

GHSA-6jj2-4q5c-x8g6 has a CVSS score of 6.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-6jj2-4q5c-x8g6?

GHSA-6jj2-4q5c-x8g6 affects the following packages: CoreWCF.NetNamedPipe (NuGet), CoreWCF.NetNamedPipe (NuGet). Ecosystems affected: NuGet.

How do I fix GHSA-6jj2-4q5c-x8g6?

Update CoreWCF.NetNamedPipe to 1.8.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6jj2-4q5c-x8g6 is resolved across your whole dependency graph.

How do I detect GHSA-6jj2-4q5c-x8g6 in my NuGet dependencies?

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

How do I mitigate GHSA-6jj2-4q5c-x8g6 if there is no patch (or I can't update yet)?

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.

Is GHSA-6jj2-4q5c-x8g6 actively exploited in the wild?

No public exploit code has been indexed for GHSA-6jj2-4q5c-x8g6 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-6jj2-4q5c-x8g6?

GHSA-6jj2-4q5c-x8g6 has an EPSS (Exploit Prediction Scoring System) score of 0.1%, placing it in the 2th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-6jj2-4q5c-x8g6?

GHSA-6jj2-4q5c-x8g6 is classified as CWE-367 (CWE-367), CWE-665 (CWE-665). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-6jj2-4q5c-x8g6 published, and has it been updated?

GHSA-6jj2-4q5c-x8g6 was published on June 19, 2026 and was last updated on June 19, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

.NET

.NET NuGet

Not in CISA KEV

MEDIUM severity

CoreWCF NetNamedPipe transport accepts attach to a pre-existing named pipe instanceGHSA-6jj2-4q5c-x8g6

MEDIUM

GHSA-6jj2-4q5c-x8g6 is a medium-severity (CVSS 6.5) CWE-367 vulnerability in CoreWCF.NetNamedPipe. A fix is available for CoreWCF.NetNamedPipe — see the affected versions and patch details below.

Also known asCVE-2026-54777

Published

Jun 19, 2026

Updated

Jun 19, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Oct 23, 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-6jj2-4q5c-x8g6.

EPSS Exploitation Probability

via FIRST.org ↗

0.1%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs2th percentile — riskier than 2% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

GHSA-6jj2-4q5c-x8g6 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 395,249 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

2 pkgs affected

.NETCoreWCF.NetNamedPipe.NETCoreWCF.NetNamedPipe

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

CoreWCF NetNamedPipe transport accepts attach to a pre-existing named pipe instance, allowing local interception of NetNamedPipe traffic. NetNamedPipe creates a shared memory object based on the listening url, then generated a unique GUID for the named pipe it will be using and saves this to the shared memory object. Then it creates the named pipe to listen for clients. This requires an attacker to race the service and create the named pipe between the service publishing the GUID to the shared memory location (which the attacker needs to read) and the service creating the named pipe itself.

Patches

Fixed in CoreWCF v1.8.1 and v1.9.1

Workarounds

None

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`CoreWCF.NetNamedPipe`	all versions	1.8.1`dotnet add package CoreWCF.NetNamedPipe --version 1.8.1`
.NETNuGet	`CoreWCF.NetNamedPipe`	≥ 1.9.0&&< 1.9.1	1.9.1`dotnet add package CoreWCF.NetNamedPipe --version 1.9.1`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for CoreWCF.NetNamedPipe, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update CoreWCF.NetNamedPipe to 1.8.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6jj2-4q5c-x8g6 is resolved across your whole dependency graph.
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.

Frequently Asked Questions

### Impact CoreWCF NetNamedPipe transport accepts attach to a pre-existing named pipe instance, allowing local interception of NetNamedPipe traffic. NetNamedPipe creates a shared memory object based on the listening url, then generated a unique GUID for the named pipe it will be using and saves this to the shared memory object. Then it creates the named pipe to listen for clients. This requires an attacker to race the service and create the named pipe between the service publishing the GUID to the shared memory location (which the attacker needs to read) and the service creating the named pipe