What is CVE-2026-53420?

CVE-2026-53420 is a high-severity vulnerability in Zoom Communications Workplace, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 8.0/10. Published 2026-10-13.

How severe is CVE-2026-53420?

High severity. CVSS v3 base score is 8.0 out of 10.

Buffer overflow in Zoom Communications Workplace

CVE-2026-53420

Buffer overflow in a Zoom Phone feature of Zoom Workplace Clients may allow an unauthenticated user to conduct a escalation of privilege via network access.

Vulnerability class: Buffer Overflow

Published 2026-10-13 · last modified 2026-10-13.

CVSS v3 metric

CVSS v3 base score 8.0 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Zoom Communications Workplace

Weakness classification (CWE)

CWE-120 — Buffer Copy without Checking Size of Input (Classic Buffer Overflow)

References

www.zoom.com/en/trust/security-bulletin/zsb-26020

Frequently asked questions

What is CVE-2026-53420?: CVE-2026-53420 is a high-severity vulnerability in Zoom Communications Workplace, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 8.0/10. Published 2026-10-13.
How severe is CVE-2026-53420?: High severity. CVSS v3 base score is 8.0 out of 10.