CVE-2026-93637 Zimbra Collaboration Suite GraphQL Batched Authentication Bypasses Pre-Auth Rate Limiting
Unauthenticated attackers can bypass pre-authentication rate limits in Zimbra Collaboration Suite by using GraphQL aliases to perform repeated password guessing.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-93637?
CVE-2026-93637 is a low-severity vulnerability in Zimbra Collaboration Suite, published on 14 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-307
Which versions are affected by CVE-2026-93637?
How do I fix CVE-2026-93637?
No fix has been published for CVE-2026-93637 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-93637 being exploited?
There is no known exploitation of CVE-2026-93637 in the wild and no public exploit code.
Sources
Also known as GHSA-gm33-c835-gc8h.