How severe is CVE-2022-39256?

CVE-2022-39256 has a CVSS score of 9/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2022-39256?

CVE-2022-39256 affects the following packages: CompositeC1.Core (NuGet). Ecosystems affected: NuGet.

How do I fix CVE-2022-39256?

Update CompositeC1.Core to 6.13 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-39256 is resolved across your whole dependency graph.

How do I detect CVE-2022-39256 in my NuGet dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for CompositeC1.Core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2022-39256 if there is no patch (or I can't update yet)?

Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

Is CVE-2022-39256 actively exploited in the wild?

No public exploit code has been indexed for CVE-2022-39256 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 CVE-2022-39256?

CVE-2022-39256 has an EPSS (Exploit Prediction Scoring System) score of 1.7%, placing it in the 77th 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 CVE-2022-39256?

CVE-2022-39256 is classified as Deserialization of Untrusted Data (CWE-502). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2022-39256 published, and has it been updated?

CVE-2022-39256 was published on September 27, 2022 and was last updated on October 28, 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

CRITICAL severity

CVE-2022-39256 — CompositeC1.Core

CRITICALFix: Orckestra/C1-CMS-Foundation#814

CVE-2022-39256 is a critical-severity (CVSS 9) Deserialization of Untrusted Data vulnerability in CompositeC1.Core. A fix is available for CompositeC1.Core — see the affected versions and patch details below.

Orckestra C1 CMS's deserialization of untrusted data allows for arbitrary code execution.

Also known asGHSA-gfhp-jgp6-838j

Published

Sep 27, 2022

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 3, 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 CVE-2022-39256.

EPSS Exploitation Probability

via FIRST.org ↗

1.7%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs77th percentile — riskier than 77% of all scored CVEsHighest risk

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

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

.NETCompositeC1.Core

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

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Orckestra C1 CMS. Authentication is required to exploit this vulnerability. The authenticated user may perform the actions unknowingly by visiting a specially crafted site.

Patches

Patched in C1 CMS v6.13

Workarounds

Upgrade to C1 CMS v6.13 or newer is required

Credit

This issue was discovered and reported by Markus Wulftange / Code White GmbH.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`CompositeC1.Core`	all versions	6.13`dotnet add package CompositeC1.Core --version 6.13`

Affected Products

1 product · 1 configurations

Application

c1 cmsorckestra

< 6.13

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for CompositeC1.Core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update CompositeC1.Core to 6.13 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-39256 is resolved across your whole dependency graph.
Workarounds
Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

Frequently Asked Questions

### Impact This vulnerability allows remote attackers to execute arbitrary code on affected installations of Orckestra C1 CMS. Authentication is required to exploit this vulnerability. The authenticated user may perform the actions unknowingly by visiting a specially crafted site. ### Patches Patched in C1 CMS v6.13 ### Workarounds Upgrade to C1 CMS v6.13 or newer is required ### Credit This issue was discovered and reported by Markus Wulftange / [Code White GmbH](https://code-white.com/en/).