What is CVE-2026-9959?

CVE-2026-9959 is a low-severity vulnerability in Google Chrome, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 3.1/10. Published 2026-05-28.

How severe is CVE-2026-9959?

Low severity. CVSS v3 base score is 3.1 out of 10.

Vulnerability in Google Chrome

CVE-2026-9959

Race in WebRTC in Google Chrome on Windows prior to 148.0.7778.216 allowed a remote attacker to leak cross-origin data via a crafted HTML page. (Chromium security severity: High)

Vulnerability class: Race Condition

EPSS: 0.000 (7.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

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

Affected products

Google Chrome — versions 148.0.7778.216
Microsoft Windows

Weakness classification (CWE)

CWE-362 — Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition)

References

chrome-cve-admin@google.com (Release Notes)
chrome-cve-admin@google.com (Permissions Required)

Frequently asked questions

What is CVE-2026-9959?: CVE-2026-9959 is a low-severity vulnerability in Google Chrome, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 3.1/10. Published 2026-05-28.
How severe is CVE-2026-9959?: Low severity. CVSS v3 base score is 3.1 out of 10.