Google Chrome FreeType Heap Buffer Overflow Vulnerability

What it is

Google Chrome uses FreeType, an open-source software library to render fonts, which contains a heap buffer overflow vulnerability in the function Load_SBit_Png when processing PNG images embedded into fonts. This vulnerability is part of an exploit chain with CVE-2020-17087 on Windows and CVE-2020-16010 on Android.

VulnCheck tracked exploitation 380 days before CISA's KEV listing. VulnCheck's broader catalog of in-the-wild exploitation evidence picked this up before it landed on CISA's formal list. Per-CVE fact about this entry; not a population claim about lead time in general.

Who's affected

Affects anyone using Chrome or Chromium as their browser. The browser is where staff log into cloud apps, banking, and client portals — exploitation can mean session theft or credential exposure for every site you're signed into.

What to do

Apply updates per vendor instructions.

If you don't have someone in-house to verify the patch deployed across every endpoint — or you're not sure whether you're affected — that's exactly the kind of triage we do. Book a free 20-minute triage call.

CISA due date

Federal deadline: November 17, 2021. Federal agencies must complete the required action by this date. For private SMBs the deadline is advisory — but treat it as a strong recommendation, especially if you handle regulated data (HIPAA, GLBA, ABA model rules).

EPSS

EPSS score: 44.3% — higher than 99% of all scored CVEs.

EPSS estimates the probability of exploitation activity in the next 30 days. Every entry on this site is already confirmed exploited, so read it as relative urgency among the things you still have open, not as permission to wait.

Score dated 2026-08-12, from the FIRST.org Exploit Prediction Scoring System.

Browse more

• All Google KEV entries
• Browsers
• All SMB-relevant KEV entries

Source

This entry comes from CISA's Known Exploited Vulnerabilities catalog, public US-Government data we pull daily. The plain-language framing and the what-to-do guidance above are ours. View the original entry on cisa.gov.