What is CVE-2026-93637?

CVE-2026-93637 is a low-severity vulnerability in Zimbra Collaboration Suite, classified under Improper Restriction of Excessive Authentication Attempts. CVSS score: 3.7/10. Published 2026-10-14.

How severe is CVE-2026-93637?

Low severity. CVSS v3 base score is 3.7 out of 10.

Vulnerability in Zimbra Collaboration Suite

CVE-2026-93637

An authentication rate-limit bypass in Zimbra Collaboration Suite 10.1.0 through 10.1.21 allows unauthenticated attackers to make repeated password guesses through GraphQL without incrementing Zimbra’s source-IP failure counter. GraphQL aliases allow multiple authentication attempts in one HTTP request.

Published 2026-10-14.

CVSS v3 metric

CVSS v3 base score 3.7 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N.

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

Zimbra Collaboration Suite

Weakness classification (CWE)

CWE-307 — Improper Restriction of Excessive Authentication Attempts

References

www.rapid7.com/blog/post/ve-breaking-zimbra-identity-boundaries-part-1 (third-party-advisory)

Frequently asked questions

What is CVE-2026-93637?: CVE-2026-93637 is a low-severity vulnerability in Zimbra Collaboration Suite, classified under Improper Restriction of Excessive Authentication Attempts. CVSS score: 3.7/10. Published 2026-10-14.
How severe is CVE-2026-93637?: Low severity. CVSS v3 base score is 3.7 out of 10.