CVE-2026-17857 in Chrome
Summary
by MITRE • 07/30/2026
Inappropriate implementation in Network in Google Chrome prior to 151.0.7922.72 allowed a remote attacker to leak cross-origin data via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 07/30/2026
This vulnerability represents a critical cross-origin data leakage issue within Google Chrome's network implementation that existed prior to version 151.0.7922.72. The flaw stems from inadequate sandboxing and origin validation mechanisms within the browser's networking stack, specifically affecting how cross-origin resources are handled during page rendering and network communication processes. The vulnerability manifests when a malicious attacker crafts a specially designed html page that exploits improper boundary checking between different origins, allowing unauthorized data access across domain boundaries. This type of vulnerability falls under the CWE-200 category of "Information Exposure" and specifically aligns with CWE-1247 which addresses "Improper Handling of Cross-Origin Resource Sharing (CORS)" scenarios. The security impact is categorized as medium severity by chromium security team but represents a significant threat to web application security and user privacy.
The technical exploitation occurs through the manipulation of browser network protocols where the vulnerability allows an attacker to construct html elements that bypass normal cross-origin restrictions during resource loading and processing. When Chrome processes these crafted pages, it fails to properly enforce same-origin policies for certain network operations, enabling data leakage between different origins. This typically involves leveraging timing attacks or memory access patterns that reveal information about resources from other domains. The vulnerability affects the browser's internal networking components including the HTTP request handling mechanism, resource loader, and cross-origin communication channels. Attackers can potentially extract sensitive data such as cookies, session tokens, or other confidential information from different origins without proper authorization.
The operational impact of this vulnerability extends beyond simple data leakage to encompass broader security implications for web applications and user privacy protection. Organizations relying on chrome-based applications face potential exposure to cross-site scripting attacks and data exfiltration attempts that could compromise user accounts and sensitive business information. The vulnerability particularly affects environments where multiple domains are accessed within the same browser session, creating attack vectors for sophisticated persistent threats. Security teams must consider this issue as part of their broader threat landscape analysis when assessing browser security posture and implementing defensive measures against advanced persistent threats. The medium severity classification reflects the fact that exploitation requires specific conditions and crafted payloads, but the potential for data compromise makes it a significant concern for enterprise security.
Mitigation strategies should prioritize immediate patch deployment to ensure all affected chrome installations receive the necessary security updates addressing the network implementation flaw. Organizations should implement additional monitoring for suspicious cross-origin requests and establish web application firewalls that can detect and block anomalous network behavior patterns associated with this vulnerability. Network administrators should consider implementing strict content security policies and regular browser security audits to identify potential exposure points. The remediation process must include comprehensive testing to verify that the patch resolves the specific network handling issues without introducing compatibility problems. Security teams should also conduct regular training on recognizing and responding to cross-origin data leakage scenarios, as this type of vulnerability often requires specialized knowledge to detect and prevent effectively.