CVE-2026-79076 in Chrome
Summary
by MITRE • 08/26/2026
Improper input validation in Sync in Google Chrome prior to 152.0.7977.65 allowed a remote attacker to obtain sensitive information via crafted network traffic. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 08/26/2026
The vulnerability identified as an improper input validation flaw within the synchronization subsystem of Google Chrome, specifically in versions prior to 152.0.7977.65, represents a significant risk to user privacy and data integrity. This issue stems from insufficient sanitization or type-checking mechanisms applied to network traffic processed by the sync engine before it is utilized for local state updates. When an attacker crafts specific malicious network packets designed to exploit these validation gaps, they can trick the browser into processing unexpected or malformed data structures. The Chromium project has classified this vulnerability with a medium security severity rating, indicating that while exploitation requires careful crafting of inputs and potentially some level of user interaction or passive exposure to hostile networks, it does not typically allow for arbitrary code execution but rather focuses on information disclosure.
From a technical perspective, the core flaw lies in how the sync service handles incoming data streams from remote servers or peer devices. Input validation is critical in this context because the browser relies on these inputs to update local bookmarks, passwords, history, and other sensitive user configurations. If the application fails to strictly enforce expected formats, lengths, or types for fields within the synchronization protocol, an attacker can inject crafted payloads that bypass internal checks. These malformed packets may cause the application to leak memory contents, expose internal state variables, or reveal details about the local environment through error messages or side-channel effects during parsing operations. The attack vector is remote, meaning a threat actor does not need physical access to the victim's machine and can potentially execute this exploit over standard internet connections by manipulating traffic directed at Chrome’s sync endpoints.
The operational impact of this vulnerability centers on unauthorized information disclosure rather than system compromise or denial of service. An attacker who successfully exploits this flaw could gain access to sensitive user data that is synchronized across devices, including browsing history, saved credentials, and potentially session tokens if they are part of the synced payload. This compromises the confidentiality aspect of the CIA triad for affected users. Furthermore, because Chrome sync often involves multiple devices linked under a single account, an initial breach on one device or through network interception could theoretically lead to broader exposure across the user’s ecosystem. The medium severity rating suggests that while the impact is serious due to the sensitivity of synced data, the complexity of exploitation and the availability of mitigations keep it from being rated as critical in this specific instance.
To mitigate the risks associated with this vulnerability, users must upgrade Google Chrome to version 152.0.7977.65 or later immediately upon release. This update contains patches that enforce stricter input validation rules within the sync module, ensuring that malformed network traffic is rejected before it can be processed into local state changes. In environments where immediate patching is not feasible, administrators should consider implementing strict egress filtering and deep packet inspection at the network perimeter to detect and block anomalous traffic patterns targeting Chrome’s synchronization endpoints. Additionally, enabling two-factor authentication on Google accounts adds a layer of defense-in-depth, reducing the value of stolen credentials even if partial information disclosure occurs.
This vulnerability aligns with Common Weakness Enumeration category CWE-20 Improper Input Validation, which covers failures to verify that input data meets expected criteria before processing. It also relates to ATT&CK technique T1537 Deceptive Traffic: Disguised Data Exfiltration, as the attack relies on crafting network traffic that appears legitimate but contains malicious payloads designed to extract information. By addressing this flaw through software updates and network monitoring, organizations can significantly reduce their exposure to data leakage attacks targeting browser synchronization features. Maintaining up-to-date browsers is the most effective defense against such logic-based vulnerabilities that exploit trust in standard communication protocols.