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Not in CISA KEV
HIGH severity

CVE-2026-58283 — Edge Chromium

HIGH

CVE-2026-58283 is a high-severity (CVSS 8.1) CWE-843 vulnerability in microsoft edge chromium. A fix is available — see the affected versions and patch details below.

Access of resource using incompatible type ('type confusion') in Microsoft Edge (Chromium-based) allows an unauthorized attacker to perform spoofing over a network.

Published
Jul 3, 2026
Updated
Jul 6, 2026
Affected
1 product
Patched
See advisory
Exploits
None indexed
Exploitation data as of Sep 30, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-58283.

EPSS Exploitation Probability

via FIRST.org ↗
0.4%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs36th percentile — riskier than 36% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2026-58283 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 380,526 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Description

Access of resource using incompatible type ('type confusion') in Microsoft Edge (Chromium-based) allows an unauthorized attacker to perform spoofing over a network.

Affected Products

1 product · 1 configurations
Application
edge chromiummicrosoft
< 150.0.4078.48
range

Detection & mitigation playbook

Vendor / appliance

  1. Detect

    Inventory every microsoft edge chromium deployment and check each version against the affected-products list above.

  2. Fix

    Apply the microsoft edge chromium security patch or hotfix for CVE-2026-58283 on the affected version, following the vendor advisory for your exact build.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.

Frequently Asked Questions

Access of resource using incompatible type ('type confusion') in Microsoft Edge (Chromium-based) allows an unauthorized attacker to perform spoofing over a network.
O3 Security · Runtime Protection

Is CVE-2026-58283 being exploited in your environment?

Detect and block the exploit chain at execution, on systems you cannot patch yet.

Protect my workloads How runtime protection works
CVE-2026-58283: Edge Chromium (High 8.1) | O3 Security