What is CVE-2022-27926?

CVE-2022-27926 is a medium-severity vulnerability in Synacor Zimbra Collaboration Suite, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2022-04-21.

How severe is CVE-2022-27926?

Medium severity. CVSS v3 base score is 6.1 out of 10.

Is CVE-2022-27926 known to be exploited?

Yes. CVE-2022-27926 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-04-03), indicating it is being actively exploited. 5 public proof-of-concept repositories are indexed.

XSS in Synacor Zimbra Collaboration Suite

CVE-2022-27926

A reflected cross-site scripting (XSS) vulnerability in the /public/launchNewWindow.jsp component of Zimbra Collaboration (aka ZCS) 9.0 allows unauthenticated attackers to execute arbitrary web script or HTML via request parameters.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2022-04-21 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.176 (97.1th percentile), scored 2026-10-19.

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 97th percentile — 97.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.176 · newest: 0.176 · change: 0.000

Affected products

Synacor Zimbra Collaboration Suite — versions 9.0.0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2023-04-03. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2023-04-24.

Required action: Apply updates per vendor instructions.

Public proof-of-concept exploits

References

wiki.zimbra.com/wiki/Zimbra_Security_Advisories (Vendor Advisory)
wiki.zimbra.com/wiki/Security_Center (Vendor Advisory)
wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P24 (Release Notes, Vendor Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2022-27926?: CVE-2022-27926 is a medium-severity vulnerability in Synacor Zimbra Collaboration Suite, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2022-04-21.
How severe is CVE-2022-27926?: Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2022-27926 known to be exploited?: Yes. CVE-2022-27926 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-04-03), indicating it is being actively exploited. 5 public proof-of-concept repositories are indexed.