Vulnerability in Microsoft Edge Chromium

CVE-2026-58616

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.

Vulnerability class: Race Condition

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (20.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 20.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-58616: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-58616?
CVE-2026-58616 is a medium-severity vulnerability in Microsoft Edge Chromium, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 4.4/10. Published 2026-08-28.
How severe is CVE-2026-58616?
Medium severity. CVSS v3 base score is 4.4 out of 10.