CVE-2026-10632
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.30%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 8.7 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
- EPSS
- 0.30% probability · 23th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-79
- Source
- cve@rapid7.com
EPSS moved from 0.4% on 24 October 2026 to 0.3% on 26 October 2026.
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.