What is CVE-2026-13999?

CVE-2026-13999 is a medium-severity vulnerability in Google Chrome, classified under Improper Input Validation. CVSS score: 4.3/10. Published 2026-06-30.

How severe is CVE-2026-13999?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Improper input validation in Google Chrome

CVE-2026-13999

Insufficient validation of untrusted input in Extensions in Google Chrome prior to 150.0.7871.47 allowed an attacker who convinced a user to install a malicious extension to perform UI spoofing via a crafted Chrome Extension. (Chromium security severity: Medium)

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published 2026-06-30 · last modified 2026-07-01.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (7.5th percentile), scored 2026-10-06.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 7th percentile — 7.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Google Chrome — versions 150.0.7871.47

Weakness classification (CWE)

CWE-20 — Improper Input Validation

References

chromereleases.googleblog.com/2026/06/stable-channel-update-for-desktop_0175352… (Release Notes)
issues.chromium.org/issues/514071697 (Permissions Required)

Frequently asked questions

What is CVE-2026-13999?: CVE-2026-13999 is a medium-severity vulnerability in Google Chrome, classified under Improper Input Validation. CVSS score: 4.3/10. Published 2026-06-30.
How severe is CVE-2026-13999?: Medium severity. CVSS v3 base score is 4.3 out of 10.