XSS in Synacor Zimbra Collaboration Suite
CVE-2026-73572
In Zimbra Collaboration (ZCS) before 10.1.17, a stored cross-site scripting (XSS) vulnerability exists in the Zimbra Classic Web Client due to insufficient sanitization of specific attachment content during inline preview. An attacker can send a crafted email containing a malicious attachment that, when previewed by a user, executes arbitrary JavaScript within the victim's browser session. Successful exploitation may allow an attacker to perform unauthorized actions on behalf of the victim user, potentially leading to data exfiltration or unauthorized access to sensitive information.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
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: 0.003 (16.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 16.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
Weakness classification (CWE)
References
- wiki.zimbra.com/wiki/Zimbra_Security_Advisories (Vendor Advisory)
- wiki.zimbra.com/wiki/Zimbra_Responsible_Disclosure_Policy (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-73572?
- CVE-2026-73572 is a medium-severity vulnerability in Synacor Zimbra Collaboration Suite, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-08-13.
- How severe is CVE-2026-73572?
- Medium severity. CVSS v3 base score is 6.1 out of 10.