In September 2025, a critical zero-day vulnerability, identified as CVE-2025-10585, was discovered in Google Chrome’s V8 JavaScript engine. This high-severity flaw, with a CVSS 3.1 score of 8.8, enables remote code execution by exploiting memory corruption techniques that bypass Chrome’s sandbox protections. It marks the sixth actively exploited Chrome zero-day vulnerability identified in 2025.
Understanding Type Confusion Vulnerabilities in V8
Type confusion vulnerabilities occur when a program misinterprets the type of an object, leading to logical errors and potential security breaches. In the context of Chrome’s V8 engine, such vulnerabilities can be particularly dangerous. The CVE-2025-10585 flaw exploits Chrome’s performance optimization systems by corrupting the inline cache (IC) mechanism during JavaScript object property access.
Security researchers have confirmed active exploitation campaigns targeting cryptocurrency wallets and conducting espionage operations. Threat actors leverage this flaw to execute arbitrary shellcode and escape Chrome’s renderer process sandbox.
Mechanism of the CVE-2025-10585 Exploit
The CVE-2025-10585 vulnerability exploits Chrome’s V8 JavaScript engine through a type confusion attack that manipulates the TurboFan just-in-time compiler’s optimization assumptions. This manipulation involves creating specially crafted Proxy objects that deceive V8’s type inference system.
During TurboFan compilation, the engine makes critical assumptions about object types based on runtime feedback. Attackers can subvert these assumptions by implementing custom getter functions that return unexpected data types, causing the compiler to generate incorrect memory access patterns.
The technical exploitation chain begins with creating a JavaScript object containing a Symbol.toPrimitive handler that returns an array when V8 expects a primitive number. When the ToNumber() conversion operation is invoked repeatedly (typically through arithmetic operations), V8’s Maglev and TurboFan compilers optimize the code path based on incorrect type assumptions.
This code demonstrates how attackers can manipulate V8’s type system to achieve memory corruption. The vulnerability allows construction of addrof and fakeobj primitives, essential building blocks for advanced exploitation techniques including return-oriented programming (ROP) chain construction.
Risk Factors and Affected Products
The CVE-2025-10585 vulnerability affects all Chrome versions prior to 140.0.7339.185 across Windows, macOS, and Linux platforms, as well as Chromium-based browsers, including Microsoft Edge, Brave, and Opera.
Exploitation Impact
The attack chain typically begins with social engineering techniques, directing victims to malicious websites containing the exploitation code. Threat intelligence reports indicate sophisticated actors are chaining this vulnerability with privilege escalation exploits to install persistent malware, steal cryptocurrency private keys, and conduct targeted surveillance operations.
The vulnerability’s network-based attack vector requires only that users visit a compromised website, making it particularly dangerous for widespread exploitation.
Google’s Threat Analysis Group has attributed some exploitation activities to commercial spyware vendors and nation-state actors, highlighting the vulnerability’s strategic value for intelligence operations. The flaw enables attackers to bypass Chrome’s multi-process architecture and site isolation features, traditionally considered robust defensive mechanisms.
Cryptocurrency security firms have reported wallet drainage attacks specifically targeting Chrome users, with stolen funds traced to addresses associated with known cybercriminal organizations. These attacks demonstrate the practical financial impact of the vulnerability beyond traditional espionage applications.
Mitigation Measures
In response to the discovery of CVE-2025-10585, Google has released an emergency security update for Chrome. Users are strongly urged to update their browsers immediately to protect against potential attacks. The new stable channel version has been updated to 140.0.7339.185/.186 for Windows and Mac, and 140.0.7339.185 for Linux.
To check your Chrome version and apply the update, navigate to the Help menu and select About Google Chrome. The browser will automatically check for and download the latest update, after which a restart will be required to apply the patch.
Conclusion
The CVE-2025-10585 type confusion vulnerability in Chrome’s V8 engine underscores the critical importance of timely software updates and vigilant cybersecurity practices. Users and organizations must remain proactive in applying security patches and educating themselves about potential threats to safeguard their digital assets.
