Cyber Resilience

CVE-2026-9966

HighUpdated

Published: 28 May 2026

Published
28 May 2026
Modified
17 June 2026
KEV Added
Patch
CVSS Score v3.1 8.3 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H
EPSS Score 0.0021 11.7th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-9966 is a high-severity External Control of Assumed-Immutable Web Parameter (CWE-472) vulnerability in Google Chrome. Its CVSS base score is 8.3 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 11.7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

Integer overflow in XML in Google Chrome on Windows prior to 148.0.7778.216 allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a crafted HTML page. (Chromium security severity: High)

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
Why these techniques?

Integer overflow enables sandbox escape from already-compromised renderer, directly mapping to exploitation for privilege escalation.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-8573Same product: Google Chrome
CVE-2026-8510Same product: Google Chrome
CVE-2026-11058Same product: Google Chrome
CVE-2026-7973Same product: Google Chrome
CVE-2026-8519Same product: Google Chrome
CVE-2026-4452Same product: Google Chrome
CVE-2026-11640Same product: Google Chrome
CVE-2026-9960Same product: Google Chrome
CVE-2026-9909Same product: Google Chrome
CVE-2026-9998Same product: Google Chrome

Affected Assets

google
chrome
≤ 148.0.7778.216

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References