CVE-2016-7201 is a high-severity (CVSS 7.5) CWE-843 vulnerability in Microsoft.ChakraCore. It is in CISA's Known Exploited Vulnerabilities catalog (added 2022-03-28) — treat it as actively exploited and patch now. A fix is available for Microsoft.ChakraCore — see the affected versions and patch details below.
ChakraCore RCE Vulnerability
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2022-03-28. Federal agencies were required to remediate by 2022-04-18.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2016-7201.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2016-7201 by exploitation likelihood (EPSS) against impact (CVSS). In the shaded patch-first corner (EPSS 50%+, CVSS 7.0+).
Where this sits among everything scored
Of 394,803 CVEs with a current EPSS score, this one falls in the 50–90% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
Microsoft.ChakraCoreReal-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
The Chakra JavaScript scripting engine in Microsoft Edge allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted web site, aka "Scripting Engine Memory Corruption Vulnerability," a different vulnerability than CVE-2016-7200, CVE-2016-7202, CVE-2016-7203, CVE-2016-7208, CVE-2016-7240, CVE-2016-7242, and CVE-2016-7243.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Microsoft.ChakraCore | all versions | 1.2.2dotnet add package Microsoft.ChakraCore --version 1.2.2 |
Affected Products
edgemicrosoftResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Microsoft Edge (Windows 10) - 'chakra.dll' Information Leak / Type Confusion Remote Code Execution
by Brian Pak · Jan 5, 2017
Microsoft Edge - 'FillFromPrototypes' Type Confusion
by Google Security Research · Nov 18, 2016
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Microsoft.ChakraCore, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update Microsoft.ChakraCore to 1.2.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-7201 is resolved across your whole dependency graph.
Workarounds
Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.
Frequently Asked Questions
Is CVE-2016-7201 in your dependencies?
Find it across NuGet, including transitive dependencies.