Inappropriate implementation in V8GHSA-m7mf-48hp-5qmr
HIGHGHSA-m7mf-48hp-5qmr is a high-severity (CVSS 8.8) Out-of-bounds Write vulnerability in CefSharp.Common. It is in CISA's Known Exploited Vulnerabilities catalog (added 2021-11-03) — treat it as actively exploited and patch now. A fix is available for CefSharp.Common — see the affected versions and patch details below.
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2021-11-03. Federal agencies were required to remediate by 2022-05-03.
- 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 GHSA-m7mf-48hp-5qmr.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
GHSA-m7mf-48hp-5qmr 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 10–50% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
CefSharp.Common.NETCefSharp.Wpf.NETCefSharp.WinForms.NETCefSharp.Wpf.HwndHostReal-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
CVE-2020-16009: Inappropriate implementation in V8
- https://chromereleases.googleblog.com/2020/11/stable-channel-update-for-desktop.html
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-16009
Google is aware of reports that exploits for CVE-2020-16009 exist in the wild.
Allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
There is currently little to no public information on the issue other than it has been flagged as High severity.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | CefSharp.Common | all versions | 86.0.241dotnet add package CefSharp.Common --version 86.0.241 |
| .NETNuGet | CefSharp.Wpf | all versions | 86.0.241dotnet add package CefSharp.Wpf --version 86.0.241 |
| .NETNuGet | CefSharp.WinForms | all versions | 86.0.241dotnet add package CefSharp.WinForms --version 86.0.241 |
| .NETNuGet | CefSharp.Wpf.HwndHost | all versions | 86.0.241dotnet add package CefSharp.Wpf.HwndHost --version 86.0.241 |
Affected Products
cefsharpcefsharpdebian linuxdebianfedorafedoraprojectchromegoogleedgemicrosoftedge chromiummicrosoftResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Inappropriate implementation in V8 in Google Chrome prior to 86.0.4240.1…
Inappropriate implementation in V8 in Google Chrome prior to 86.0.4240.1…
Inappropriate implementation in V8 in Google Chrome prior to 86.0.4240.1…
Inappropriate implementation in V8 in Google Chrome prior to 86.0.4240.1…
Inappropriate implementation in V8 in Google Chrome prior to 86.0.4240.1…
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for CefSharp.Common, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update CefSharp.Common to 86.0.241 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-m7mf-48hp-5qmr 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.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 6 Supplementary | chromium-browser-0:86.0.4240.183-1.el6_10 | RHSA-2020:4974 |
Frequently Asked Questions
Is GHSA-m7mf-48hp-5qmr in your dependencies?
Find it across NuGet, including transitive dependencies.