What is CVE-2026-7978?

CVE-2026-7978 is a high-severity vulnerability in Apple macOS, classified under Protection Mechanism Failure. CVSS score: 8.1/10. Published 2026-05-06.

How severe is CVE-2026-7978?

High severity. CVSS v3 base score is 8.1 out of 10.

Vulnerability in Apple macOS

CVE-2026-7978

Inappropriate implementation in Companion in Google Chrome on Mac prior to 148.0.7778.96 allowed a remote attacker to perform OS-level privilege escalation via malicious network traffic. (Chromium security severity: Medium)

Published 2026-05-06 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.003 (22.3th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 22nd percentile — 22.3% 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: 0.003 · change: +0.001

Affected products

Apple macOS
Google Chrome — versions 148.0.7778.96

Weakness classification (CWE)

CWE-693 — Protection Mechanism Failure

References

chromereleases.googleblog.com/2026/05/stable-channel-update-for-desktop.html (Vendor Advisory)
issues.chromium.org/issues/497828892 (Permissions Required, Issue Tracking)

Frequently asked questions

What is CVE-2026-7978?: CVE-2026-7978 is a high-severity vulnerability in Apple macOS, classified under Protection Mechanism Failure. CVSS score: 8.1/10. Published 2026-05-06.
How severe is CVE-2026-7978?: High severity. CVSS v3 base score is 8.1 out of 10.