CVE-2025-6554 Google Chromium V8 Type Confusion Vulnerability
Google Chromium V8 contains a type confusion vulnerability that could allow a remote attacker to perform arbitrary read/write via a crafted HTML page. This vulnerability could affect multiple web browsers that utilize Chromium, including, but not limited to, Google Chrome, Microsoft Edge, and Opera.
From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.
Should You Worry?
- CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 2 Jul 2025.
- Rated High severity (CVSS 8.1, scored by CISA).
- It has been in the catalogue for 492 days. Systems still unpatched now have almost certainly been scanned for it.
What It Is
Type confusion in V8 in Google Chrome prior to 138.0.7204.96 allowed a remote attacker to perform arbitrary read/write via a crafted HTML page. (Chromium security severity: High)
Affected Versions
| Product | Versions |
|---|---|
| Google Chrome | 138.0.7204.96 to before 138.0.7204.96 |
From the public CVE record, as supplied by the vendor. Always confirm against the vendor advisory.
What To Do Now
- 1
Find it
Search your asset inventory and external attack surface for Google Chromium V8. Include cloud images, appliances and anything a supplier runs for you.
Attack Surface Management - 2
Fix it
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Vulnerability Management - 3
Hunt for compromise
If an affected system was reachable before you patched, assume it may have been hit. Check logs, new accounts, web shells and outbound connections from the date of exposure.
Incident Response - 4
Prove it is fixed
Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.
Penetration Testing
The Compliance Clock
General guidance, not legal advice. Your obligations depend on your sector, scope and jurisdiction.
Not Sure If You Are Exposed?
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