GHSA-j9c2-gr6m-pp45 — C1CMS.Assemblies
HIGHGHSA-j9c2-gr6m-pp45 is a high-severity (CVSS 7.6) Server-Side Request Forgery (SSRF) vulnerability in C1CMS.Assemblies. A fix is available for C1CMS.Assemblies — see the affected versions and patch details below.
Deserialization of untrusted data in C1 CMS.
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-j9c2-gr6m-pp45.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
GHSA-j9c2-gr6m-pp45 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 379,842 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
C1CMS.AssembliesReal-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
C1 CMS is an open-source, .NET based Content Management System (CMS). Versions prior to 6.12 allow an authenticated user to exploit Server Side Request Forgery (SSRF) by causing the server to make arbitrary GET requests to other servers in the local network or on localhost. The attacker may also truncate arbitrary files to zero size (effectively delete them) leading to denial of service (DoS) or altering application logic. The authenticated user may unknowingly perform the actions by visiting a specially crafted site. Patched in C1 CMS v6.12, no known workarounds exist.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | C1CMS.Assemblies | all versions | 6.12.8122.18346dotnet add package C1CMS.Assemblies --version 6.12.8122.18346 |
Affected Products
c1 cmsorckestraDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for C1CMS.Assemblies, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update C1CMS.Assemblies to 6.12.8122.18346 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-j9c2-gr6m-pp45 is resolved across your whole dependency graph.
Workarounds
Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.
Frequently Asked Questions
Is GHSA-j9c2-gr6m-pp45 in your dependencies?
Find it across NuGet, including transitive dependencies.