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CVE-2026-58276 Microsoft CVE debrief

A use-after-free vulnerability exists in Microsoft Edge (Chromium-based). An unauthorized attacker could exploit this vulnerability to execute code over a network. This type of vulnerability occurs when the program attempts to access memory that has already been freed or deleted. The vulnerability could be exploited by tricking a user into visiting a specially crafted webpage, allowing the attacker to execute arbitrary code on the user's system. System administrators and users of Microsoft Edge (Chromium-based) should be aware of this vulnerability and apply patches or mitigations as recommended.

Vendor
Microsoft
Product
Edge Chromium
CVSS
HIGH 7.5
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

System administrators and users of Microsoft Edge (Chromium-based) should be aware of this vulnerability and apply patches or mitigations as recommended. This vulnerability could affect operators who manage Microsoft Edge deployments, platform administrators who oversee Chromium-based browser configurations, and security teams responsible for vulnerability management and incident response.

Technical summary

The CVE-2026-58276 vulnerability is a use-after-free issue in Microsoft Edge (Chromium-based). This type of vulnerability occurs when the program attempts to access memory that has already been freed or deleted. An attacker could potentially exploit this vulnerability by tricking a user into visiting a specially crafted webpage, allowing the attacker to execute arbitrary code on the user's system.

Defensive priority

High

Recommended defensive actions

  • Apply patches or updates provided by Microsoft
  • Monitor for suspicious activity
  • Use secure browsing practices
  • 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

Evidence notes

The CVE record was published on 2026-07-03T21:17:02.573Z and was last modified on 2026-07-07T05:16:54.107Z. The NVD entry is currently Analyzed. This vulnerability affects Microsoft Edge (Chromium-based) and could allow an unauthorized attacker to execute code over a network. The vulnerability is a use-after-free issue, which occurs when the program attempts to access memory that has already been freed or deleted. To verify the affected scope, defenders should review the official CVE record and vendor advisory.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-58276 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-58276

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

  • CVE-2026-58276 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-58276

    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.