# CVE-2023-37580: Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability

Source: https://junglewise.ai/threats/cve-2023-37580-synacor-zimbra-collaboration-suite-zcs-cross-site-scripting-xss  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2023-07-27. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-2023-37580 · Severity: critical · CVSS 6.1 · Exploited in the wild · Published 2023-07-27

Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting (XSS) vulnerability in the Zimbra Classic Web Client. The flaw allows remote attackers to impact the confidentiality and integrity of data via improper neutralization of input during web page generation.

Technologies: [Synacor Zimbra Collaboration Suite (ZCS)](https://junglewise.ai/threats/technologies/zimbra-collaboration-suite-zcs). Vendors: [Synacor](https://junglewise.ai/threats/vendors/synacor).

## Quick answers

**Is CVE-2023-37580 exploited in the wild?** Yes. CVE-2023-37580 is known to be exploited in the wild, first recorded on 27 July 2023. Treat it as urgent.

**How severe is CVE-2023-37580?** Critical severity, with a CVSS score of 6.1, published 27 July 2023.

**Which products and versions are affected?** Synacor Zimbra Collaboration Suite (ZCS) 8 before 8.8.15 Patch 41.

**Is there a fix for CVE-2023-37580?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2023-37580 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2023-37580?** Check whether you run Synacor Zimbra Collaboration Suite (ZCS). Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Synacor Zimbra Collaboration Suite (ZCS) 8 before 8.8.15 Patch 41

## Timeline

- 2023-07-27: disclosed: Date added to CISA KEV catalog
- 2023-07-27: kev added
- 2023-07-27: advisory
- 2023-07-27: exploited: Reported as exploited in the wild per CISA KEV inclusion.

## Related threats

- [Zimbra Collaboration Suite OS command injection in SMTP](https://junglewise.ai/threats/cve-2026-73570-zimbra-collaboration-suite-os-command-injection-in-smtp)
- [Synacor Zimbra Collaboration Suite XSS in Classic UI](https://junglewise.ai/threats/cve-2025-48700-synacor-zimbra-collaboration-suite-xss-in-classic-ui)
- [Synacor Zimbra Collaboration Suite stored XSS in Classic UI](https://junglewise.ai/threats/cve-2025-66376-synacor-zimbra-collaboration-suite-stored-xss-in-classic-ui)
- [Synacor Zimbra Collaboration Suite file inclusion in RestFilter servlet](https://junglewise.ai/threats/cve-2025-68645-synacor-zimbra-collaboration-suite-file-inclusion-in-restfilter)
- [Synacor Zimbra Collaboration Suite XSS in Classic Web Client](https://junglewise.ai/threats/cve-2025-27915-synacor-zimbra-collaboration-suite-xss-in-classic-web-client)