CVERadar
HIGH · CVSS 3.1 8.1CISA KEV · added 2025-07-02Public PoCEPSS 14.14% (p97)Threat level 60

CVE-2025-6554: Google Chromium V8 Type Confusion Vulnerability

Google · Chromium V8 · NVD published 2025-07-01 · posted 2025-07-02 · last modified 2026-06-17

What it is

Type confusion in V8 in Google Chrome prior to 138.0.7204.96 allowed a remote attacker to perform arbitrary read/write via a crafted HTML page. (Chromium security severity: High)

WeaknessCWE-843
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N (source: 134c704f-9b21-4f2e-91b3-4a467353bcc0)
CISA due date2025-07-23 (for US federal agencies under BOD; a good deadline for everyone)
ATT&CK tacticsInitial Access → Execution

Exploitation evidence

First exploit evidence seen: 2025-07-02 (earliest date across the sources below).

Exploited in the wild

  • CISA KEV: listed since 2025-07-02. Source

Public exploit code

GitHub proof-of-concept repositories

9 public repositories from 8 accounts, first seen 2025-07-05. Most starred: mistymntncop/CVE-2025-6554 (45 stars), view repository.

Verify before running: public PoCs can be malicious. Read the code and only run it in an isolated lab. A PoC means exploit code is public, not that this CVE is exploited in the wild.

Sources: CISA KEV · nomi-sec/PoC-in-GitHub.

Defend the Chain

The attack chain for CVE-2025-6554 laid across the MITRE ATT&CK Enterprise tactics. Solid cards come from the MITRE CTID KEV mappings; dashed cards are inferred by CVERadar from the CWE or description. Correct defences are real ATT&CK mitigations for that technique.

Threat level 60/100
Defender level 1 · 0 XP
Chain links broken: 0/3

Reconnaissance

Resource Development

Initial Access

Execution

Persistence

Privilege Escalation

Stealth

Defense Impairment

Credential Access

Discovery

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

Pick a red technique card on the board, then choose the defence that stops it.

Defend against T1189 Drive-by Compromise CTID: exploitation technique

Victims are tricked into visiting malicious web pages crafted to trigger memory corruption, which can lead to arbitrary code execution.

How to fix it

CISA required action

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. (source: CISA KEV)

Fixed versions

  • google chrome: upgrade to 138.0.7204.96 or later
  • google chrome: upgrade to 138.0.7204.92 or later

Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.

Vendor advisories and patches

MITRE ATT&CK mitigations for this chain

  • M1050 Exploit Protection (for T1189, T1203) : Security applications that look for behavior used during exploitation such as Windows Defender Exploit Guard (WDEG) and the Enhanced Mitigation Experience Toolkit (EMET) can be used to mitigate some exploitation behavior. Control flow integrity checking is another way to potentially identify and stop a software exploit
  • M1051 Update Software (for T1189, T1203) : Ensuring that all browsers and plugins are kept updated can help prevent the exploit phase of this technique. Use modern browsers with security features turned on.
  • M1048 Application Isolation and Sandboxing (for T1189, T1203) : Browser sandboxes can be used to mitigate some of the impact of exploitation, but sandbox escapes may still exist. Other types of virtualization and application microsegmentation may also mitigate the impact of client-side exploitation. The risks of additional exploits and weaknesses in implementation may still exist
  • M1021 Restrict Web-Based Content (for T1189, T1059) : Adblockers can help prevent malicious code served through ads from executing in the first place. Script blocking extensions can also help to prevent the execution of JavaScript. Consider disabling browser push notifications from certain applications and browsers.
  • M1017 User Training (for T1189) : Train users to be aware of access or manipulation attempts by an adversary to reduce the risk of successful spearphishing, social engineering, and other techniques that involve user interaction.
  • M1033 Limit Software Installation (for T1059) : Prevent user installation of unrequired command and scripting interpreters.
  • M1045 Code Signing (for T1059) : Where possible, only permit execution of signed scripts.
  • M1042 Disable or Remove Feature or Program (for T1059) : Disable or remove any unnecessary or unused shells or interpreters.
  • M1038 Execution Prevention (for T1059) : Use application control where appropriate. For example, PowerShell Constrained Language mode can be used to restrict access to sensitive or otherwise dangerous language elements such as those used to execute arbitrary Windows APIs or files (e.g., `Add-Type`).
  • M1049 Antivirus/Antimalware (for T1059) : Anti-virus can be used to automatically quarantine suspicious files.

Detection Generic guidance

  • Initial Access: Alert on unusual requests to the affected service (odd paths, oversized payloads, exploit strings) in WAF, reverse-proxy and application logs.
  • Execution: Watch for the service process spawning shells or script interpreters (cmd.exe, powershell, sh, bash, python) via EDR process-tree rules.

Response checklist Generic guidance

  1. Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
  2. Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
  3. Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
  4. Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.

Sources