What is CVE-2026-70309?

CVE-2026-70309 is a security advisory published by Microsoft Security Response Center (MSRC) with Medium severity. Microsoft Edge (Chromium-based) Security Feature Bypass Vulnerability

Which CVE IDs does CVE-2026-70309 cover?

CVE-2026-70309 covers the following CVE IDs: CVE-2026-70309. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of CVE-2026-70309?

CVE-2026-70309 has a CVSS v3 base score of 5.4, published by Microsoft Security Response Center (MSRC).

Which products are affected by CVE-2026-70309?

CVE-2026-70309 affects 1 product, including: Microsoft Edge (Chromium-based).

CVE-2026-70309MediumCVSS 5.4

Microsoft Edge (Chromium-based) Security Feature Bypass Vulnerability

Vendor

Microsoft Security Response Center (MSRC)

Published

August 28, 2026

Last Modified

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🔗 CVE IDs covered (1)

CVE-2026-70309 →

📋 Description

Origin validation error in Microsoft Edge (Chromium-based) allows an unauthorized attacker to bypass a security feature over a network.

🎯 Affected products1

Microsoft Edge (Chromium-based)

✅ Remediation

KBRelease Notes (Security Update) — fixed build 150.0.4078.65

🔗 References (2)

advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70309
referencehttps://docs.microsoft.com/en-us/DeployEdge/microsoft-edge-relnotes-security