CVE-2026-58289 — Edge Chromium
CRITICALCVE-2026-58289 is a critical-severity (CVSS 9) CWE-843 vulnerability in microsoft edge chromium. 1 public exploit reference exists, so weaponization risk is real. 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 execute code over a network.
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- 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-2026-58289.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-58289 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,386 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 execute code over a network.
Affected Products
edge chromiummicrosoftResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Microsoft Edge 150.0.4078.48 - RCE
by banyamer · Aug 10, 2026
Detection & mitigation playbook
Vendor / applianceDetect
Inventory every microsoft edge chromium deployment and check each version against the affected-products list above.
Fix
Apply the microsoft edge chromium security patch or hotfix for CVE-2026-58289 on the affected version, following the vendor advisory for your exact build.
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
Is CVE-2026-58289 being exploited in your environment?
Detect and block the exploit chain at execution, on systems you cannot patch yet.