CVE-2026-33368

Name: CVE-2026-33368
Creator: NVD / NIST
Published: 2026-03-20T14:16:15.81+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 0.22%

Last modified Jun 17, 2026

CVE-2026-33368 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. Zimbra Collaboration Suite (ZCS) 10.0 and 10.1 contains a reflected cross-site scripting (XSS) vulnerability in the Classic Webmail REST interface (/h/rest). The application fails to properly sanitize user-supplied input, allowing an unauthenticated attacker to inject malicious JavaScript into a crafted URL. EPSS estimates a 0.22% chance of exploitation in the next 30 days.

Description

Zimbra Collaboration Suite (ZCS) 10.0 and 10.1 contains a reflected cross-site scripting (XSS) vulnerability in the Classic Webmail REST interface (/h/rest). The application fails to properly sanitize user-supplied input, allowing an unauthenticated attacker to inject malicious JavaScript into a crafted URL. When a victim user accesses the link, the injected script executes in the context of the Zimbra webmail application, which could allow the attacker to perform actions on behalf of the victim.

Metrics

CVSS 3.1

6.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

0.22%

12.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Synacor	Zimbra Collaboration Suite	>= 10.0.0, < 10.1.16

References

https://wiki.zimbra.com/wiki/Security_CenterRelease Notes, Vendor Advisory
https://wiki.zimbra.com/wiki/Zimbra_Releases/10.1.16#Security_FixesRelease Notes
https://wiki.zimbra.com/wiki/Zimbra_Responsible_Disclosure_PolicyProduct
https://wiki.zimbra.com/wiki/Zimbra_Security_AdvisoriesVendor Advisory

Timeline

Published: Mar 20, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-33368?

How severe is CVE-2026-33368?

CVE-2026-33368 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.22% probability of exploitation in the next 30 days.

How do I fix CVE-2026-33368?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-33368?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST