What is CVE-2026-3909?

CVE-2026-3909 is a high-severity vulnerability in Apple macOS, classified under Out-of-bounds Write. CVSS score: 8.8/10. Published 2026-03-13.

How severe is CVE-2026-3909?

High severity. CVSS v3 base score is 8.8 out of 10.

Is CVE-2026-3909 known to be exploited?

Yes. CVE-2026-3909 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-03-13), indicating it is being actively exploited. 2 public proof-of-concept repositories are indexed.

Buffer overflow in Apple macOS

CVE-2026-3909

Out of bounds write in Skia in Google Chrome prior to 146.0.7680.75 allowed a remote attacker to perform out of bounds memory access via a crafted HTML page. (Chromium security severity: High)

Vulnerability class: Buffer Overflow

Published 2026-03-13 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.023 (83.4th percentile), scored 2026-10-19.

Low probability of exploitation in the next 30 days, but still tracked. 83rd percentile — 83.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.016 · newest: 0.023 · change: +0.007

Affected products

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2026-03-13. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2026-03-27.

Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Public proof-of-concept exploits

References

issues.chromium.org/issues/491421267 (Permissions Required)
chromereleases.googleblog.com/2026/03/stable-channel-update-for-desktop_13.html (Release Notes, Vendor Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2026-3909?: CVE-2026-3909 is a high-severity vulnerability in Apple macOS, classified under Out-of-bounds Write. CVSS score: 8.8/10. Published 2026-03-13.
How severe is CVE-2026-3909?: High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2026-3909 known to be exploited?: Yes. CVE-2026-3909 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-03-13), indicating it is being actively exploited. 2 public proof-of-concept repositories are indexed.