CVE-2026-121228
Description
A type confusion flaw was found in the V8 component of the Chromium browser.
Upstream bug(s):
Statement
Red Hat Product Security rates the severity of this flaw as determined by the Google Chrome Security Advisory.
Mitigation
--- CME Mitigation Guidance (2026-11-04) ---
Disclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from https://cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure.
The highest-value action is to disable JIT compilation via the --jitless flag or enforce V8 sandbox restrictions to eliminate JIT optimization pathways: upgrade to Google Chrome 157.0.8103.38+ (or the fixed Chromium builds), which resolves the type confusion vulnerability in the V8 JavaScript engine to prevent arbitrary code execution inside the sandbox, closing crafted HTML page. Until patched, this is a concern on all platforms running Chromium or Google Chrome where users can browse untrusted websites, so restrict user navigation to untrusted or external websites and consider running browsers with JIT compilation disabled. As a compensating measure, enforce Control Flow Integrity and Shadow Call Stack to validate indirect call targets and return addresses, deploy EDR agents to detect anomalous process execution and post-compromise behavioral patterns, and verify Address Space Layout Randomization is active to require an additional information leak for exploitation. These controls limit blast radius and contain exploitation, but they do not fix the underlying type confusion defect — apply the upstream patch to fully remediate.
Highest-impact CME: CME-919 JIT Compiler Hardening (JIT Restriction / V8 Sandbox) (high)
Understanding the Weakness (CWE)
Other
Technical Impact: Varies by Context
When the product accesses the resource using an incompatible type, this could trigger logical errors because the resource does not have expected properties.
Availability,Integrity,Confidentiality
Technical Impact: Read Memory; Modify Memory; Execute Unauthorized Code or Commands; DoS: Crash, Exit, or Restart
If a memory buffer is accessed using an incompatible type, and the allocated buffer is smaller than the type that the code is attempting to access, then an attacker could read or write memory outside the bounds of the buffer, leading to a crash or possibly code execution.
Frequently Asked Questions
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