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CVE-2026-12437 Google CVE debrief

A use after free vulnerability was discovered in Google Chrome's WebShare feature on Windows prior to version 149.0.7827.155. This vulnerability, CVE-2026-12437, allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a crafted HTML page. The vulnerability is considered critical and affects users of Google Chrome on Windows. Successful exploitation could allow an attacker to escape the sandbox, potentially leading to arbitrary code execution or other malicious activities.

Vendor
Google
Product
Chrome
CVSS
HIGH 8.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-17
Original CVE updated
2026-06-18
Advisory published
2026-06-17
Advisory updated
2026-06-18

Who should care

This vulnerability affects users of Google Chrome on Windows. Successful exploitation could allow an attacker to escape the sandbox, potentially leading to arbitrary code execution or other malicious activities. Operators, platform administrators, vulnerability management teams, and security teams should be aware of this vulnerability and take immediate action to update their browsers and implement additional security measures.

Technical summary

The vulnerability is a use after free issue in the WebShare feature of Google Chrome on Windows. This occurs when the program attempts to use memory after it has been freed, which can lead to unpredictable behavior. An attacker who has compromised the renderer process can exploit this vulnerability by providing a crafted HTML page, potentially allowing them to escape the sandbox and execute arbitrary code. The vulnerability affects Google Chrome on Windows prior to version 149.0.7827.155.

Defensive priority

High

Recommended defensive actions

  • Update Google Chrome to version 149.0.7827.155 or later
  • Ensure that all users of Google Chrome on Windows are aware of this vulnerability and take immediate action to update their browsers
  • Monitor for any suspicious activity that could be related to this vulnerability
  • Implement additional security measures such as sandboxing and isolation to prevent exploitation
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record was published on 2026-06-17T13:19:58.863Z and was last modified on 2026-06-18T13:47:47.770Z. The NVD entry is currently Analyzed. This information is based on the NVD entry and the CVE record. The vulnerability affects Google Chrome on Windows prior to version 149.0.7827.155. The CVE record and NVD entry provide additional context and details about the vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-12437 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-12437

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-12437 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-12437

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.