Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
CVE-2026-58616
Microsoft Microsoft Edge (Chromium-based) — Copilot Chat (Microsoft Edge) Information Disclosure Vulnerability
AV AC PR UI S C I A CVSS EPSS %ile KEV
N H L R C L N N 3.0 .0029 20.1 —
AFFECTED
Product Versions Fixed
Microsoft Edge (Chromium-based) - – —
Microsoft Edge for Android 1.0.0.0 – —
Microsoft Edge for iOS 1.0.0.0 – —
Microsoft Edge for Linux 1.0.0 – —
Microsoft Edge for MAC 1.0.0.0 – —
Microsoft Edge for Windows 1.0.0.0 – —
TIMELINE
Jul 1 Reserved by microsoft
Aug 28 Published (CNA: microsoft)
Aug 31 RESCORED — CVE-2026-58616 (Microsoft Edge (Chromium-based)). CVSS 4.4 → 3 (NVD).
Description
Concurrent execution using shared resource with improper synchronization ('race condition') in Copilot Chat (Microsoft Edge) allows an authorized attacker to disclose information over a network.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
|---|
| July 1, 2026 | Reserved | Reserved by microsoft |
| August 28, 2026 | Published | Published (CNA: microsoft) |
| August 31, 2026 | RESCORED | RESCORED — CVE-2026-58616 (Microsoft Edge (Chromium-based)). CVSS 4.4 → 3 (NVD). |
Affected
Affected products and packages — 6 rows
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|
| Microsoft | Microsoft Edge (Chromium-based) | — | - | — |
| Microsoft | Microsoft Edge for Android | — | 1.0.0.0 | — |
| Microsoft | Microsoft Edge for iOS | — | 1.0.0.0 | — |
| Microsoft | Microsoft Edge for Linux | — | 1.0.0 | — |
| Microsoft | Microsoft Edge for MAC | — | 1.0.0.0 | — |
| Microsoft | Microsoft Edge for Windows | — | 1.0.0.0 | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-58616 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 Sunday, October 4, 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.
