Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
AV AC PR UI S C I A CVSS EPSS %ile KEV N L N R C H H H 9.6 .0107 62.1 —
AFFECTED Product Versions Fixed Microsoft Edge (Chromium-based) 1.0.0.0 – —
TIMELINE Jul 24 Reserved by microsoft Aug 3 Published (CNA: microsoft) Aug 4 RESCORED — CVE-2026-66321 (Microsoft Edge (Chromium-based)). CVSS 7.4 → 9.6 (NVD).
Access of resource using incompatible type ('type confusion') in Microsoft Edge (Chromium-based) allows an unauthorized attacker to execute code over a network.
| Date | Event | Detail |
|---|---|---|
| July 24, 2026 | Reserved | Reserved by microsoft |
| August 3, 2026 | Published | Published (CNA: microsoft) |
| August 4, 2026 | RESCORED | RESCORED — CVE-2026-66321 (Microsoft Edge (Chromium-based)). CVSS 7.4 → 9.6 (NVD). |
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|---|---|---|---|
| Microsoft | Microsoft Edge (Chromium-based) | — | 1.0.0.0 | — |
Authoritative record: CVE-2026-66321 at cve.org
Vendors: microsoft
Weaknesses: CWE-843
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-66321 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.