CVE-2025-10585 — Type Confusion in Chrome’s V8 Engine (Zero-Day) Vulnerability Analysis Report — By CyberDudeBivash

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Executive Summary

Google has patched CVE-2025-10585, a zero-day type confusion vulnerability in the V8 JavaScript & WebAssembly engine of Google Chrome. This vulnerability is actively exploited in the wild and poses serious risk — memory corruption, arbitrary code execution, potentially full browser compromise. Users of Chrome (and Chromium-based browsers) should update immediately to avoid being targeted.

Vulnerability Details

AttributeDetail
Name / IDCVE-2025-10585
ComponentChrome’s V8 JavaScript / WebAssembly engine Help Net Security+2The Hacker News+2
Type of VulnerabilityType Confusion — misinterpreting an object’s type leading to memory safety violation TechRadar+2Help Net Security+2
Discovered byGoogle Threat Analysis Group (TAG) on September 16, 2025 Security Affairs+2Bitdefender+2
Exploitation StatusAlready being exploited in the wild (zero-day) Help Net Security+2TechRadar+2
Affected VersionsChrome versions prior to 140.0.7339.185/.186 (Windows/Mac) and 140.0.7339.185 (Linux) Help Net Security+2Bitdefender+2

How It Works

  • Type Confusion: An attacker crafts JavaScript or WebAssembly code so that V8 treats data as a different type (e.g. object vs. double or wrong structure). This misinterpretation lets them corrupt memory (heap), bypass type safety, possibly execute arbitrary code. TechRadar+2Help Net Security+2

  • Attack Vector: User visits a malicious or compromised web page. JavaScript is executed in browser context. No download or user interaction beyond visiting page required in some cases. Bitdefender+2isidefense.com+2

  • Sandbox / Privilege Escapes: After compromising V8, attack can try to break out of the renderer sandbox or escalate further depending on environment. Bitdefender+1

Impact & Risk

  • Arbitrary Code Execution: On user machine, via Chrome; could lead to installation of malware, spyware, credential theft, etc.

  • Browser Compromise: Extension hijacking, tab injection, exfiltration of data stored in browser (cookies, localStorage).

  • High Exposure: Chrome has ~70% browser market share; many endpoints likely exposed. Chromium-based derivatives may share vulnerability domains. TechRadar+2Help Net Security+2

  • Low Complexity / No Authentication Required: Attacker only needs to lure user to malicious site; often no need for user action beyond visiting. isidefense.com+1

Patch & Mitigation

StepAction
ImmediateUpdate Chrome to 140.0.7339.185/.186 on Windows/Mac, 140.0.7339.185 on Linux. Bitdefender+2Help Net Security+2
Ensure Auto-UpdatesConfirm that automatic updates are enabled and latest security builds are being received. Help Net Security
Update Chromium-Based BrowsersEdge, Brave, Opera, Vivaldi, etc. Monitor for patches and apply them. Help Net Security+1

Detection & Defensive Measures

  • Log monitoring: Look for crashes or renderer process instability, especially related to V8 engine.

  • Endpoint EDR: Watch for suspicious process behavior initiated via browser, e.g. loading new DLLs or executing shell commands after visiting web pages.

  • Network indicators: Malicious sites delivering exploit payloads; block / filter suspicious JavaScript delivery sources.

  • Browser Hardening: Disable untrusted scripts; use content security policy (CSP); disable V8 JIT where feasible for high-sensitivity users.

  • Sandbox monitoring: Hardening sandbox limits, verifying exploit attempt logs.

Timeline

Who Is At Risk

  • Individual users who browse web without immediate updates.

  • Enterprises with delayed update policies or restrictive IT management.

  • Users of Chromium-based alternative browsers.

  • High-value targets: journalists, activists, enterprises with sensitive browser-based workflows.

Action Checklist — CyberDudeBivash Style

  •  Immediately update Chrome on all OSes to patched versions: 140.0.7339.185/.186 as applicable.

  •  Ensure all devices in organization have auto-update enabled; track versions centrally.

  •  Audit browser usage: identify endpoints still on vulnerable versions.

  •  Update or patch other Chromium-based browsers in scope.

  •  Deploy network / web filter to block access to malicious or unknown sites; block exploit heavy JS content.

  •  Communicate to users / staff about avoiding suspicious sites; encourage browser restarts to apply patches.

  •  Incorporate this vulnerability into risk register; schedule review of similar V8 or JS engine-type flaws.

Conclusion

CVE-2025-10585 is a high-impact zero-day in one of the most critical components of modern web infrastructure. Because it’s actively exploited, patching is not optional — it’s urgent. The combination of type confusion, widespread target base, and the power of V8 means attackers have fertile ground if defenders delay. Update now, monitor carefully, and prepare for similar browser-engine threats in future.


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#CyberDudeBivash #CVE2025-10585 #ChromeZeroDay #V8Engine #BrowserSecurity #TypeConfusion #ExploitInTheWild #PatchNow #ThreatIntel #Infosec

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