Use after free in CefSharp

Exploitation

Confirmed: listed in the CISA Known Exploited Vulnerabilities catalog.

CVSS

not scored

EPSS

• CVE-2020-16017: 2.73% estimated exploitation activity in the next 30 days; percentile 86.10 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

CVE-2020-16017: Use after free in site isolation - https://chromereleases.googleblog.com/2020/11/stable-channel-update-for-desktop11.html - https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-16017 Google is aware of reports that exploits for CVE-2020-16013 and CVE-2020-16017 exist in the wild. There is currently little to no public information on the issue other than it has been flagged as High severity.

Published by the source

27 Nov 2020, 20:13 UTC

Last modified by the source

1 Feb 2023, 05:05 UTC

Source last checked

26 Oct 2026, 16:59 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-gvqv-779r-4jgp

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# Patch Next advisory brief: CVE-2020-16017

Advisory: Use after free in CefSharp
IDs: CVE-2020-16017, GHSA-gvqv-779r-4jgp
Record: https://patchnext.com/advisories/cve-2020-16017 (revision 1, source checked 26 Oct 2026, 16:59 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Unrated
Exploitation: confirmed: listed in the CISA Known Exploited Vulnerabilities catalog.
Vendor response: Vendor fix available; fixed versions by package: cefsharp.wpf.hwndhost 86.0.241; cefsharp.common 86.0.241; cefsharp.wpf 86.0.241; cefsharp.winforms 86.0.241. A vendor fix does not mean a deployment is fixed.

## Affected components
- NuGet cefsharp.wpf.hwndhost: affected < 86.0.241; fixed in 86.0.241
- NuGet cefsharp.common: affected < 86.0.241; fixed in 86.0.241
- NuGet cefsharp.wpf: affected < 86.0.241; fixed in 86.0.241
- NuGet cefsharp.winforms: affected < 86.0.241; fixed in 86.0.241

## Suggested inspection (read-only)
- NuGet cefsharp.wpf.hwndhost: check the installed version with your package manager.
- NuGet cefsharp.common: check the installed version with your package manager.
- NuGet cefsharp.wpf: check the installed version with your package manager.
- NuGet cefsharp.winforms: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on cefsharp.wpf.hwndhost, cefsharp.common, cefsharp.wpf, cefsharp.winforms.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://www.cisa.gov/known-exploited-vulnerabilities-catalog (CISA added CVE-2020-16017 to the Known Exploited Vulnerabilities catalog on 2021-11-03.)
- Verified: https://github.com/advisories/GHSA-gvqv-779r-4jgp (GitHub-reviewed advisory GHSA-gvqv-779r-4jgp lists affected ranges: NuGet cefsharp.common >=0 =0 =0 =0 <86.0.241)

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