CVE-2026-78895 in Chrome
Summary
by MITRE • 08/26/2026
Information leak in Paint in Google Chrome prior to 152.0.7977.65 allowed a remote attacker to bypass web origin policy via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 08/26/2026
The vulnerability identified as an information leak within the paint component of Google Chrome, specifically affecting versions prior to 152.0.7977.65, represents a significant breach in web origin policy enforcement. This flaw allows a remote attacker to bypass standard browser security boundaries by leveraging a crafted HTML page. The core issue lies in how the rendering engine handles graphical operations and memory management during the painting process. When a webpage is rendered, Chrome allocates specific regions of video or system memory for drawing images, text, and other visual elements. In this instance, improper handling of these allocations resulted in residual data from previous renderings or unrelated processes remaining accessible within the allocated buffers after they were ostensibly cleared or reused. This behavior creates a side-channel through which sensitive information can be exfiltrated without direct access to the underlying memory space via traditional read operations.
From a technical perspective, this vulnerability is classified under CWE-200 as an Information Exposure, specifically falling into categories related to exposure of sensitive information to unauthorized actors. The mechanism relies on the browser's ability to render content from different origins while maintaining strict isolation between them. However, due to the flaw in the paint component, data that should have been isolated within one origin could be inadvertently exposed when another origin triggers a repaint or re-rendering operation. An attacker constructs an HTML page containing malicious JavaScript code designed to exploit this timing and memory state inconsistency. By carefully crafting canvas operations or image loading sequences, the attacker can trigger conditions where the browser fails to properly sanitize the graphical buffer before making it available for inspection by the script running in the context of a different origin. This effectively breaks the same-origin policy, which is fundamental to web security, allowing scripts from one domain to read data belonging to another.
The operational impact of this vulnerability is severe because it undermines the trust model that browsers use to protect user privacy and data integrity. Web applications rely on the assumption that code running in a specific origin cannot access resources or state information from other origins unless explicitly permitted via mechanisms like CORS. By bypassing these restrictions, an attacker could potentially steal session cookies, authentication tokens, personal identifiable information displayed within iframes, or sensitive application states hosted on legitimate websites. This capability enables sophisticated phishing attacks where the malicious page can mimic a trusted site while simultaneously harvesting credentials or financial data from it. Furthermore, since this is a remote code execution vector that does not require user interaction beyond visiting a webpage, it poses a high risk for drive-by download scenarios and large-scale exploitation campaigns targeting users who visit compromised or maliciously hosted sites.
In terms of industry frameworks, this vulnerability aligns with the MITRE ATT&CK technique T1056, which covers Input Capture, specifically keylogging or screen capture via browser vulnerabilities, although in this case it is more accurately described as data exfiltration through memory leakage rather than direct input interception. It also relates to T1078, Valid Accounts, if the leaked information includes session tokens that allow impersonation of legitimate users. The Chromium security severity rating of High reflects the potential for widespread impact and the ease with which an attacker can construct a proof-of-concept exploit using standard web technologies like HTML5 Canvas API or WebGL contexts to trigger the paint-related memory leak.
Mitigation strategies primarily involve updating Google Chrome to version 152.0.7977.65 or later, where these issues have been addressed through improved memory management and stricter enforcement of origin boundaries during rendering operations. For organizations unable to immediately patch all endpoints, network-level controls such as Content Security Policy headers can help mitigate some risks by restricting the sources from which scripts are loaded, although this is not a complete defense against browser-side vulnerabilities. Users should ensure that automatic updates are enabled for their browsers and avoid visiting untrusted websites until patches are applied. Additionally, security teams should monitor for indicators of compromise related to unusual network traffic patterns or unexpected memory usage spikes in Chrome processes, which may indicate active exploitation attempts targeting this specific flaw.