CVE-2026-33372

low-risk

Published 2026-03-20

An issue was discovered in Zimbra Collaboration (ZCS) 10.0 and 10.1. A cross-site request forgery (CSRF) vulnerability exists in Zimbra Webmail due to improper validation of CSRF tokens. The application accepts CSRF tokens supplied within the request body instead of requiring them through the expected request header. An attacker can exploit this issue by tricking an authenticated user into submitting a crafted request. This may allow unauthorized actions to be performed on behalf of the victim.

Do I need to act?

0.03% chance of exploitation

EPSS score — low exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 5.4/10 Medium

NETWORK / LOW complexity

Affected Products (1)

Zimbra Collaboration Suite

Affected Vendors

Synacor

References (4)

Vendor Advisory https://wiki.zimbra.com/wiki/Security_Center

Release Notes https://wiki.zimbra.com/wiki/Zimbra_Releases/10.1.16#Security_Fixes

Product https://wiki.zimbra.com/wiki/Zimbra_Responsible_Disclosure_Policy

Vendor Advisory https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories

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low-risk

Severity 21/34 · High

Exploitability 0/34 · Minimal

Exposure 5/34 · Minimal