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CVE-2026-5866 Google CVE debrief

CVE-2026-5866 is a high-severity vulnerability in Google Chrome prior to version 147.0.7727.55. It is a use-after-free issue in the Media component that allows remote attackers to execute arbitrary code inside a sandbox via a crafted HTML page. The vulnerability has a CVSS score of 8.8 and is rated as High severity. Users of Google Chrome should update to the latest version to mitigate this vulnerability.

Vendor
Google
Product
Chrome
CVSS
HIGH 8.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-04-08
Original CVE updated
2026-07-24
Advisory published
2026-04-08
Advisory updated
2026-07-24

Who should care

This vulnerability affects users of Google Chrome, particularly those with version prior to 147.0.7727.55. The vulnerability has been rated as High severity with a CVSS score of 8.8. Operators, platform administrators, vulnerability management teams, and security teams should review and mitigate this vulnerability.

Technical summary

The vulnerability is a use-after-free issue in the Media component of Google Chrome. This type of vulnerability occurs when a program tries to use memory after it has been freed, which can lead to arbitrary code execution. The vulnerability can be exploited by a remote attacker via a crafted HTML page, allowing the attacker to execute arbitrary code inside a sandbox. The affected product is Google Chrome prior to version 147.0.7727.55.

Defensive priority

High

Recommended defensive actions

  • Apply the official patch by updating Google Chrome to version 147.0.7727.55 or later.
  • Monitor for suspicious activity, such as unusual browser behavior.
  • Implement compensating controls, such as network segmentation and access controls.
  • Review and verify affected systems and components.
  • Track exceptions and retest remediated assets.
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review.
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The CVE record was published on 2026-04-08T22:16:26.130Z and was last modified on 2026-07-24T08:10:00.150Z. The NVD entry is currently Analyzed. The vulnerability affects Google Chrome users with version prior to 147.0.7727.55. Evidence is limited to public sources and CVE details. Defenders should verify affected systems and review vendor advisories.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-5866 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-5866

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

  • CVE-2026-5866 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-5866

    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.