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CVE-2026-58299 Microsoft CVE debrief

A high-severity vulnerability, CVE-2026-58299, exists in Microsoft Edge for Android, enabling unauthorized attackers to execute code over a network by exploiting a time-of-check time-of-use (toctou) race condition. This vulnerability has significant implications for organizations using Microsoft Edge for Android, as it could allow attackers to gain control over affected systems. Security teams should assess their deployments and prioritize patching to prevent potential code execution attacks. The vulnerability's high severity and potential impact necessitate prompt attention and action. Additionally, security teams should conduct a thorough review of their Microsoft Edge for Android deployments and monitor for any suspicious activity that could indicate exploitation attempts. It is crucial to verify the affected scope and review the official advisory for guidance on mitigation and remediation.

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

Security teams responsible for managing Microsoft Edge for Android deployments should prioritize patching this vulnerability to prevent potential code execution attacks.

Technical summary

CVE-2026-58299 is a time-of-check time-of-use (toctou) race condition vulnerability in Microsoft Edge for Android. The vulnerability has a CVSS score of 7.5 and is classified as HIGH severity. An unauthorized attacker could exploit this vulnerability to execute code over a network.

Defensive priority

Patching this vulnerability is crucial to prevent potential code execution attacks. Security teams should prioritize remediation efforts based on their organization's risk assessment and implement compensating controls if patching is not immediately feasible. The vulnerability's high severity and potential impact on Microsoft Edge for Android deployments necessitate prompt attention and action. Additionally, security teams should conduct a thorough review of their Microsoft Edge for Android deployments and monitor for any suspicious activity that could indicate exploitation attempts.

Recommended defensive actions

  • Apply the latest security patches for Microsoft Edge for Android
  • Conduct a thorough review of the organization's Microsoft Edge for Android deployments
  • Implement compensating controls, such as network segmentation or monitoring, if patching is not immediately feasible

Evidence notes

The CVE record was published on 2026-07-03T21:17:04.907Z and was last modified on 2026-07-07T05:16:55.330Z. The NVD entry is currently Undergoing Analysis. Microsoft has provided a security update guide for this vulnerability. The vulnerability affects Microsoft Edge for Android, and its exploitation could lead to code execution over a network. The CVSS score of 7.5 indicates high severity. Security teams should verify the affected scope and review the official advisory for guidance.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-58299 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-58299

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

  • CVE-2026-58299 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-58299

    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.