CVE-2026-121189
Description
An use after free flaw was found in the Browser 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 prevent browser navigation to untrusted web content and enforce memory mitigations within the Chromium Browser component: upgrade to Google Chrome 157.0.8103.38 (or the fixed Chromium builds), which resolves the use-after-free memory corruption flaw in the Browser component, closing crafted HTML page. Until patched, this is a concern on systems running Chromium rendering untrusted web content across any platform, so restrict user browsing to trusted sites and avoid opening untrusted HTML pages. As a compensating measure, Enforce Address Space Layout Randomization to randomize process memory and hinder address reuse, Enforce non-executable permissions on heap and data pages using the NX/XD bit to block injected shellcode execution, Enable Full RELRO and PIE to ensure position-independent layouts and make the Global Offset Table read-only, Enforce Control Flow Integrity and Shadow Call Stack to validate indirect call targets against vtable corruption, and Deploy Endpoint Detection and Response agents to detect anomalous code injection and unauthorized child process execution. These controls limit blast radius and contain exploitation, but they do not fix the underlying use-after-free defect — apply the upstream patch to fully remediate.
Highest-impact CME: CME-101 ASLR (Address Space Layout Randomization) (medium)
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory
The use of previously freed memory may corrupt valid data, if the memory area in question has been allocated and used properly elsewhere.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If chunk consolidation occurs after the use of previously freed data, the process may crash when invalid data is used as chunk information.
Confidentiality
Technical Impact: Read Memory
Read operations on freed memory can sometimes leak sensitive information instead of causing a crash
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If malicious data is entered before chunk consolidation can take place, it may be possible to take advantage of a write-what-where primitive to execute arbitrary code. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.
Frequently Asked Questions
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