CVE-2026-121072 in Chrome
Summary
by MITRE • 11/03/2026
Uninitialized resource in Skia in Google Chrome prior to 157.0.8103.38 allowed a remote attacker to obtain cross-origin data via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 11/03/2026
The vulnerability identified as an uninitialized resource issue within the Skia graphics library, which serves as the core 2D graphic interface for Google Chrome prior to version 157.0.8103.38, represents a significant memory safety flaw with direct implications for web security and data isolation. This defect occurs when the rendering engine fails to properly initialize specific memory structures or object states before they are accessed during the processing of graphical content. In the context of browser architecture, Skia handles the heavy lifting of rasterizing vector graphics, text, and images into pixels on the screen. When an uninitialized resource is utilized, it may contain stale data from previous operations or random garbage values left in memory. This lack of deterministic state can lead to unpredictable behavior during rendering, which attackers can exploit to bypass security boundaries that rely on correct object initialization for proper access control checks.
From a technical perspective, this flaw aligns with CWE-457, which describes the use of an uninitialized variable or resource. The operational impact is particularly severe because it facilitates cross-origin data leakage, a violation of the Same-Origin Policy (SOP) that is fundamental to web security. By crafting a malicious HTML page containing specific graphical elements or scripts that trigger this uninitialized state in Skia, a remote attacker can manipulate how Chrome renders content from different origins. The exploitation likely involves causing the browser to read memory contents associated with one origin while rendering context belonging to another, effectively allowing the attacker to exfiltrate sensitive data such as cookies, session tokens, or private document content that should remain isolated within their respective browsing contexts. This bypasses the sandboxing mechanisms designed to prevent cross-site scripting and data theft attacks.
The severity of this vulnerability is classified as Medium by Chromium security standards, reflecting its potential for exploitation but also acknowledging the complexity often required to reliably trigger such memory safety issues in modern browsers with advanced mitigations like ASLR and DEP. However, given that it enables direct access to cross-origin data, the practical risk remains high for users visiting compromised or malicious websites. The attack vector is remote and requires user interaction only in the sense of loading a crafted webpage, making it suitable for drive-by download style attacks where no further action from the victim is needed beyond navigation. This places the vulnerability squarely within the ATT&CK framework under techniques related to browser exploitation and data exfiltration via web browsers, specifically leveraging memory corruption or state confusion to bypass isolation policies.
Mitigation strategies primarily involve applying the official patch provided in Google Chrome version 157.0.8103.38 or later, which addresses the initialization logic within Skia to ensure all resources are properly set before use. For organizations unable to update immediately, network-level controls such as web application firewalls can be configured to detect and block requests containing suspicious graphical payloads known to trigger this flaw, although detection is challenging due to the variability of exploit code. Additionally, enabling strict Content Security Policy headers on internal applications can limit the impact if a breach occurs by restricting where data can be sent externally. Users should ensure their browsers are updated automatically or manually check for updates regularly to maintain protection against such memory safety vulnerabilities that continue to pose risks despite years of security hardening efforts in modern web engines.