CVE-2026-17842 in Chrome
Summary
by MITRE • 07/30/2026
Inappropriate implementation in Chrome for iOS in Google Chrome on iOS prior to 151.0.7922.72 allowed a remote attacker who convinced a user to engage in specific UI gestures to bypass same origin policy 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 policy bypass in Google Chrome for iOS that emerged from an inadequate implementation of security controls within the mobile browser's rendering engine. The flaw existed in versions prior to 151.0.7922.72 and enabled remote attackers to exploit specific user interaction patterns through carefully crafted HTML content. The vulnerability stems from insufficient validation of user gestures and their associated permissions, creating a pathway for malicious actors to circumvent the fundamental same origin policy that protects web applications from unauthorized cross-domain access. This weakness specifically affects iOS users who may be tricked into performing particular UI interactions that inadvertently grant malicious domains elevated privileges.
The technical execution of this vulnerability relies on the manipulation of user interface gestures within the Chrome for iOS environment, where certain touch and interaction patterns can be coerced to bypass security boundaries that normally prevent one origin from accessing resources from another. Attackers could construct HTML pages containing malicious JavaScript that would trigger specific gesture sequences when users interacted with the page in predetermined ways. This allows the exploitation of the browser's security model through what appears to be legitimate user behavior, making detection and prevention particularly challenging. The vulnerability operates at the intersection of UI interaction handling and cross-origin resource management, creating a unique attack surface that leverages the trust model inherent in mobile browser environments where user gestures are often interpreted as implicit permissions.
The operational impact of this vulnerability extends beyond simple information disclosure or data theft, as it fundamentally undermines the security architecture that web browsers implement to protect users from malicious actors. When successfully exploited, the bypass allows attackers to access sensitive resources and data from different origins that should normally be isolated from each other. This capability could enable sophisticated attacks including credential theft, session hijacking, or access to private user data across different domains. The medium severity classification reflects the specific nature of the exploit requirements, which necessitate user interaction and specific gesture sequences, but the potential for escalation remains significant as attackers can combine this vulnerability with other techniques to create more comprehensive attacks.
The flaw aligns with common weakness enumerations such as CWE-284, which addresses improper access control mechanisms, and relates to ATT&CK technique T1059.001 for command and scripting interpreter, where the vulnerability could be leveraged to execute malicious code through browser-based attack vectors. It also connects to T1566 for phishing attacks, as the exploitation typically requires user engagement through social engineering techniques that convince victims to perform specific gestures on malicious pages. This vulnerability demonstrates how mobile browser security models must account for gesture-based interactions and their potential to be manipulated to bypass traditional security controls. The implementation issue specifically highlights the challenges of enforcing security boundaries in touch-based environments where user intention can be ambiguous and easily manipulated.
Mitigation strategies for this vulnerability require immediate deployment of Chrome for iOS version 151.0.7922.72 or later, which includes patches addressing the specific gesture handling implementation flaws. Organizations should also implement network-level monitoring to detect unusual patterns of cross-origin resource access attempts that might indicate exploitation activity. Browser security configurations should be reviewed to ensure that gesture-based permission models are properly enforced and that users receive appropriate warnings when interacting with potentially malicious content. Additionally, user education programs should emphasize the importance of being cautious when performing specific UI gestures on unfamiliar websites, particularly in mobile environments where such interactions can have more severe security implications than traditional desktop browsing scenarios.