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CVE-2026-58294 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 a program attempts to access memory that has already been freed or deleted. In the context of Microsoft Edge, this could allow an attacker to execute arbitrary code on a user's system if they can convince the user to visit a specially crafted webpage. The impact of such a vulnerability can be significant, potentially allowing attackers to gain control over a user's system or steal sensitive information.

Vendor
Microsoft
Product
Microsoft Edge (Chromium-based)
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

Users of Microsoft Edge (Chromium-based) should apply patches to prevent exploitation. Additionally, security teams and IT administrators responsible for managing and securing systems that utilize Microsoft Edge should be aware of this vulnerability and take steps to ensure that all instances of the browser are updated to the latest version. This vulnerability also highlights the importance of monitoring for suspicious activity and having incident response plans in place in case of a potential exploit.

Technical summary

The vulnerability is caused by a use-after-free issue in Microsoft Edge (Chromium-based). An attacker can exploit this vulnerability by convincing a user to visit a specially crafted webpage, allowing the attacker to execute code over a network. This vulnerability highlights the importance of keeping software up-to-date, as patches are often released to address such issues. The technical details of this vulnerability involve the improper handling of memory, specifically the use of memory after it has been freed. This can lead to a range of potential attacks, including the execution of arbitrary code.

Defensive priority

High

Recommended defensive actions

  • Apply patches provided by Microsoft
  • Ensure Microsoft Edge (Chromium-based) is up-to-date
  • Monitor for suspicious activity
  • 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 2026-07-03T21:17:04.293Z and was last modified on 2026-07-07T05:16:55.183Z. The NVD entry is currently Undergoing Analysis. The information provided is based on the CVE record and NVD entry, which may not be comprehensive or up-to-date. Further verification and analysis are recommended to fully understand the scope and impact of this vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-58294 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-58294

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

  • CVE-2026-58294 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-58294

    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.