Google Chromium Portals Use-After-Free Vulnerability
What it is
Google Chromium Portals contains a use-after-free vulnerability that allows a remote attacker, who has compromised the renderer process, to potentially perform a sandbox escape via a crafted HTML page. This vulnerability affects web browsers that utilize Chromium, including Google Chrome and Microsoft Edge.
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.
CISA action 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).
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.
Severity
CVSS base score: 9.6 — CRITICAL
Weakness classification: CWE-416
Source
Pulled daily from the public cisagov/kev-data mirror (CC0). View the original entry on cisa.gov. CISA KEV is US-Government public-domain data; we add the SMB-vertical framing and the coping action above.