# CVE-2020-15999: Heap buffer overflow in CefSharp

Source: https://junglewise.ai/threats/cve-2020-15999-google-chrome-freetype-heap-buffer-overflow-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2020-10-27. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-2020-15999 · Severity: critical · CVSS 3.1 · Exploited in the wild · Published 2020-10-27

A heap buffer overflow vulnerability exists in the FreeType font rendering library, specifically within the Load_SBit_Png function when processing PNG images embedded in fonts. A remote attacker can exploit this via a crafted HTML page to cause heap corruption, potentially leading to arbitrary code execution.

Technologies: [CefSharp.Common (NuGet)](https://junglewise.ai/threats/technologies/cefsharp-common), [CefSharp.WinForms (NuGet)](https://junglewise.ai/threats/technologies/cefsharp-winforms), [CefSharp.Wpf (NuGet)](https://junglewise.ai/threats/technologies/cefsharp-wpf), [CefSharp.Wpf.HwndHost (NuGet)](https://junglewise.ai/threats/technologies/cefsharp-wpf-hwndhost). Vendors: [Google](https://junglewise.ai/threats/vendors/google), [NuGet](https://junglewise.ai/threats/vendors/nuget).

## Quick answers

**Is CVE-2020-15999 exploited in the wild?** Yes. CVE-2020-15999 is known to be exploited in the wild, first recorded on 3 November 2021. Treat it as urgent.

**How severe is CVE-2020-15999?** Critical severity, with a CVSS score of 3.1, published 27 October 2020.

**Which products and versions are affected?** CefSharp.Common (NuGet) ECOSYSTEM:introduced=0,fixed=85.3.130; CefSharp.WinForms (NuGet) ECOSYSTEM:introduced=0,fixed=85.3.130; CefSharp.Wpf (NuGet) ECOSYSTEM:introduced=0,fixed=85.3.130; CefSharp.Wpf.HwndHost (NuGet) ECOSYSTEM:introduced=0,fixed=85.3.130.

**Is there a fix for CVE-2020-15999?** Yes. CefSharp.Common (NuGet): upgrade to 85.3.130 or later; CefSharp.WinForms (NuGet): upgrade to 85.3.130 or later; CefSharp.Wpf (NuGet): upgrade to 85.3.130 or later; CefSharp.Wpf.HwndHost (NuGet): upgrade to 85.3.130 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2020-15999 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2020-15999?** Check whether you run Google Chrome Freetype, CefSharp.Common (NuGet), CefSharp.WinForms (NuGet) or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- CefSharp.Common (NuGet): upgrade to 85.3.130 or later

  ```sh
  dotnet add package CefSharp.Common --version 85.3.130
  ```

- CefSharp.WinForms (NuGet): upgrade to 85.3.130 or later

  ```sh
  dotnet add package CefSharp.WinForms --version 85.3.130
  ```

- CefSharp.Wpf (NuGet): upgrade to 85.3.130 or later

  ```sh
  dotnet add package CefSharp.Wpf --version 85.3.130
  ```

- CefSharp.Wpf.HwndHost (NuGet): upgrade to 85.3.130 or later

  ```sh
  dotnet add package CefSharp.Wpf.HwndHost --version 85.3.130
  ```


## Affected products

- Google Chrome prior to 86.0.4240.111
- FreeType FreeType

## Identifiers

- CVE-2020-15999
- GHSA-pv36-h7jh-qm62

## Timeline

- 2020-10-20: patched: Stable channel update for desktop 86.0.4240.111 released.
- 2021-11-03: kev added: Added to CISA Known Exploited Vulnerabilities Catalog.
- 2021-11-03: disclosed: NVD publication date.

## Related threats

- [CefSharp.Common path traversal in FolderSchemeHandlerFactory](https://junglewise.ai/threats/cve-2026-48796-cefsharp-common-path-traversal-in-folderschemehandlerfactory)
- [CefSharp affected by incorrect handle provided in unspecified circumstances in Mojo on Windows](https://junglewise.ai/threats/cefsharp-affected-by-incorrect-handle-provided-in-unspecified-958dc7cd)
- [CefSharp affected by libvpx's heap buffer overflow in vp8 encoding](https://junglewise.ai/threats/cefsharp-affected-by-libvpx-s-heap-buffer-overflow-in-vp8-encoding-d2f3d8f8)
- [CefSharp affected by heap buffer overflow in WebP](https://junglewise.ai/threats/cefsharp-affected-by-heap-buffer-overflow-in-webp-e15c2d7a)
- [Use after free in Animation](https://junglewise.ai/threats/cve-2022-0609-google-chromium-animation-use-after-free-vulnerability)