# CVE-2025-6554: Google Chromium V8 type confusion in JavaScript engine

Source: https://junglewise.ai/threats/cve-2025-6554-google-chromium-v8-type-confusion-in-javascript-engine  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-07-02. Updated: 2026-05-15  
License: CC BY 4.0 with a link back

CVE-2025-6554 · Severity: critical · CVSS 8.1 · Exploited in the wild · Published 2025-07-02

Google Chrome and other Chromium-based browsers (like Microsoft Edge and Opera) are affected by a critical security flaw in their JavaScript engine. By tricking a user into visiting a specially crafted website, an attacker can gain the ability to read or write data within the browser's memory. This could lead to the theft of sensitive information or the execution of malicious code on the user's device. This vulnerability is known to be actively exploited in the wild.

Technologies: [Google Chrome](https://junglewise.ai/threats/technologies/chrome), [Google Chromium](https://junglewise.ai/threats/technologies/chromium), [Google Chromium V8](https://junglewise.ai/threats/technologies/chromium-v8), [Microsoft Edge](https://junglewise.ai/threats/technologies/edge), [Opera Software Opera](https://junglewise.ai/threats/technologies/opera). Vendors: [Google](https://junglewise.ai/threats/vendors/google), [Microsoft](https://junglewise.ai/threats/vendors/microsoft), [Opera Software](https://junglewise.ai/threats/vendors/opera-software).

## Quick answers

**Is CVE-2025-6554 exploited in the wild?** Yes. CVE-2025-6554 is known to be exploited in the wild, first recorded on 2 July 2025. Treat it as urgent.

**How severe is CVE-2025-6554?** Critical severity, with a CVSS score of 8.1, published 2 July 2025.

**Which products and versions are affected?** Google Chrome prior to 138.0.7204.96; Google Chromium prior to 138.0.7204.96; Microsoft Edge All versions based on affected Chromium releases; Opera Software Opera All versions based on affected Chromium releases.

**Is there a fix for CVE-2025-6554?** A patch was published on 2025-06-30: Fixed in Chrome version 138.0.7204.96 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2025-6554 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2025-6554?** Check whether you run Google Chrome, Google Chromium, Google Chromium V8 or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A type confusion vulnerability (CWE-843) exists in the V8 JavaScript engine within Google Chromium. The flaw occurs when the engine incorrectly interprets the type of an object, allowing for out-of-bounds memory access. A remote, unauthenticated attacker can exploit this by hosting a malicious HTML page; when a user visits the page, the attacker can perform arbitrary memory read and write operations. This can be used as a primitive for remote code execution (RCE) or to bypass security sandboxes. The vulnerability is confirmed to be exploited in the wild and is patched in Chrome version 138.0.7204.96 and later.

## Affected products

- Google Chrome prior to 138.0.7204.96
- Google Chromium prior to 138.0.7204.96
- Microsoft Edge All versions based on affected Chromium releases
- Opera Software Opera All versions based on affected Chromium releases

## Timeline

- 2025-06-30: disclosed: Initial disclosure by Google Chrome team
- 2025-06-30: patched: Fixed in Chrome version 138.0.7204.96
- 2025-07-02: kev added: Added to CISA Known Exploited Vulnerabilities catalog

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