CVE-2017-11871 is a high-severity (CVSS 7.5) Buffer Overflow vulnerability in Microsoft.ChakraCore. A fix is available for Microsoft.ChakraCore — see the affected versions and patch details below.
Chakra Core vulnerable to privilege escalation due to reading an invalid pointer
EPSS Exploitation Probability
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
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
ChakraCore and Microsoft Edge in Windows 10 1703, 1709, and Windows Server, version 1709 allows an attacker to gain the same user rights as the current user, due to how the scripting engine handles objects in memory, aka "Scripting Engine Memory Corruption Vulnerability". When trying to get inlineCaches for a ScriptFunctionWithInlineCache, if the function got redefered and was not reparsed, the function body (and inlineCache on function body) won’t be there, potentially leading to a privilege escalation.
This CVE ID is unique from CVE-2017-11836, CVE-2017-11837, CVE-2017-11838, CVE-2017-11839, CVE-2017-11840, CVE-2017-11841, CVE-2017-11843, CVE-2017-11846, CVE-2017-11858, CVE-2017-11859, CVE-2017-11861, CVE-2017-11862, CVE-2017-11866, CVE-2017-11869, CVE-2017-11870, and CVE-2017-11873.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Microsoft.ChakraCore | all versions | 1.7.4dotnet add package Microsoft.ChakraCore --version 1.7.4 |
Affected Products
chakracoremicrosoftedgemicrosoftDetection & 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 1.7.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2017-11871 is resolved across your whole dependency graph.
Workarounds
Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process.
Frequently Asked Questions
Is CVE-2017-11871 in your dependencies?
Find it across NuGet, including transitive dependencies.