PatchSiren cyber security CVE debrief

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.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-03T21:17:03.640Z and has not been modified since then. The NVD entry is currently Undergoing Analysis.