CVE-2026-121080 in Chrome
Summary
by MITRE • 11/03/2026
Use after free in Codecs in Google Chrome prior to 157.0.8103.38 allowed a remote attacker to read memory inside the sandbox via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 11/03/2026
The vulnerability identified as a use-after-free condition within the Codecs component of Google Chrome prior to version 157.0.8103.38 represents a critical memory safety flaw that undermines the browser's sandboxing mechanisms. This type of error occurs when an application continues to use a pointer after it has been freed, leading to undefined behavior and potential exploitation by malicious actors. In this specific instance, the defect resides in how Chrome handles media codecs, which are responsible for encoding and decoding audio and video data streams. When processing crafted HTML pages containing specially constructed media elements or scripts that trigger codec operations, the browser fails to properly manage memory allocation and deallocation cycles associated with these complex multimedia structures.
The technical root cause involves a race condition or logic error where references to previously released memory objects are retained and subsequently accessed by the rendering engine during playback or decoding processes. Because modern browsers rely heavily on sandboxing to isolate untrusted web content from the host operating system, any breach of this isolation is particularly severe. The use-after-free flaw allows an attacker to manipulate heap metadata or overwrite adjacent memory structures with controlled data. By carefully crafting the payload within a malicious HTML page, an adversary can achieve arbitrary read access to memory regions that are normally protected by the browser's security boundaries. This capability effectively bypasses the sandbox, granting the attacker visibility into sensitive information stored in the process memory space.
The operational impact of this vulnerability is significant due to its remote exploitability and high severity rating assigned by Chromium developers. A victim merely needs to visit a maliciously crafted webpage for the attack to be triggered without any additional user interaction such as clicking or downloading files. Once exploited, an attacker can read arbitrary memory contents from inside the sandboxed renderer process. This could lead to the exfiltration of sensitive data including session cookies, authentication tokens, private keys, or other confidential information stored in browser memory. Furthermore, while the primary impact described is reading memory, use-after-free vulnerabilities are often precursors to more severe exploits such as arbitrary code execution if combined with additional techniques like heap spraying or type confusion attacks.
To mitigate this risk, users must immediately update Google Chrome to version 157.0.8103.38 or later where these memory management issues have been corrected by the development team. The fix likely involves strengthening reference counting mechanisms and ensuring that pointers are nullified after deallocation within the codec subsystem. From a defensive posture perspective, organizations should enforce strict browser update policies to ensure all endpoints run patched versions of Chromium-based browsers. Additionally, deploying content security policies can help restrict the execution of untrusted scripts and media resources, reducing the attack surface available to potential adversaries attempting to leverage this vulnerability through web pages.
This incident aligns with Common Weakness Enumeration identifier CWE-416 which describes use after free errors as a prevalent class of software vulnerabilities resulting from improper memory management practices in C and C++ based applications like Chrome's core components. It also relates to MITRE ATT&CK technique T1059 Command and Scripting Interpreter if the vulnerability is leveraged for further exploitation, although the immediate impact here focuses on information disclosure via sandbox escape. Security teams should monitor for indicators of compromise related to unusual memory access patterns or network connections originating from browser processes following visits to untrusted web content. Continuous monitoring and rapid patch deployment remain essential defenses against such high-severity vulnerabilities that target foundational components like media codecs in widely used software ecosystems.