CVE-2026-121241
Description
An use after free flaw was found in the Navigation 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 enforce Control Flow Integrity and Shadow Call Stack to validate indirect function call targets and vtables during Navigation object handling: upgrade to Google Chrome 157.0.8103.38 (or the fixed Chromium builds), which fixes a use-after-free defect in the Navigation component, closing crafted HTML page. Until patched, this is a concern on all platforms running affected Chromium and Google Chrome browsers, so prevent users from navigating to untrusted crafted HTML pages and restrict access to unknown web destinations. As a compensating measure, instrument memory allocations with tag checks using runtime memory error detection like KASAN or HWASan to trap runtime use-after-free dereferences, enable Address Space Layout Randomization to impede attackers from predicting code and data addresses, enforce non-executable heap memory permissions via NX/XD bit to block execution of injected shellcode, enable Full RELRO and PIE to enforce position-independent executable layouts and read-only relocation tables, and deploy EDR agents to monitor for anomalous child processes and code injection patterns following a potential sandbox escape. 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-113 Control Flow Integrity (CFI / Shadow Call Stack) (high)
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.
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