CVE-2026-10632: Zimbra Collaboration Suite Classic Web Client Reflected Cross-Site Scripting via Document Editor Packages Parameter
A reflected cross-site scripting vulnerability in the Classic Web Client of Zimbra Collaboration Suite (ZCS) allows an attacker to inject JavaScript through the packages parameter of the /h/rest document editor. The editor inserts package names into script attributes without HTML encoding. When combined with CVE-2026-50053, an attacker with an ordinary Zimbra account can supply their own authentication token and document identifiers in a URL and execute JavaScript in another signed-in user's Zimbra browser session when that user opens the URL. This permits reading mailbox data and performing authenticated actions as the victim. The issue affects ZCS 10.1.16 and was remediated in 10.1.17.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Zimbra Collaboration Suite (ZCS) Classic Web Clientto a version that resolves this vulnerability.Fixed in 10.1.17
Event History
Frequently Asked Questions
Who can exploit this issue, and what interaction is required?
The described exploit chain requires an attacker with an ordinary Zimbra account and CVE-2026-50053. The attacker must cause a signed-in Zimbra user to open a crafted URL; no elevated attacker privileges are described.
What is the likely impact if exploitation succeeds?
JavaScript executes in the victim's signed-in Zimbra browser session. This can allow the attacker to read mailbox data and perform authenticated actions as the victim.
Which deployments are identified as affected, and what version fixes it?
ZCS 10.1.16 is identified as affected. The issue was remediated in ZCS 10.1.17.