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CVE-2026-58289 Microsoft CVE debrief

A critical type confusion vulnerability CVE-2026-58289 exists in Microsoft Edge (Chromium-based). An unauthorized attacker can exploit this vulnerability to execute code over a network. The CVE record was published on 2026-07-03T21:17:03.640Z and was last modified on 2026-07-07T05:16:54.660Z. This vulnerability is classified as a type confusion issue, which occurs when a variable, object, or data is used in an unintended way, bypassing security checks. Security teams and administrators responsible for managing Microsoft Edge (Chromium-based) deployments should prioritize patching this vulnerability to prevent potential code execution attacks. The CVSS score for this vulnerability is 9, indicating a critical severity level. The CVSS vector is CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H. Evidence is limited, and defenders should verify the official CVE record and NVD entry for the latest information.

Vendor
Microsoft
Product
Microsoft Edge (Chromium-based)
CVSS
CRITICAL 9
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-03
Original CVE updated
2026-07-07
Advisory published
2026-07-03
Advisory updated
2026-07-07

Who should care

Security teams and administrators responsible for managing Microsoft Edge (Chromium-based) deployments should prioritize patching this vulnerability to prevent potential code execution attacks.

Technical summary

The vulnerability is caused by a type confusion issue in Microsoft Edge (Chromium-based). This allows an attacker to execute code over a network. The CVSS score for this vulnerability is 9, indicating a critical severity level. The CVSS vector is CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H.

Defensive priority

High

Recommended defensive actions

  • Apply the official patch from Microsoft as soon as possible
  • Verify that Microsoft Edge (Chromium-based) is updated to the latest version
  • Monitor network traffic for potential exploitation attempts
  • Implement additional security controls to detect and prevent code execution attacks

Evidence notes

The CVE record was published on 2026-07-03T21:17:03.640Z and was last modified on 2026-07-07T05:16:54.660Z. The NVD entry is currently Undergoing Analysis. The vulnerability is related to CWE-843. Evidence is limited, and defenders should verify the official CVE record and NVD entry for the latest information. The CVE record was obtained from a trusted source and has not been modified since its publication.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-58289 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-58289

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

  • CVE-2026-58289 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-58289

    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.