---
title: "CVE-2026-50053: Zimbra Collaboration Suite - Stored XSS"
description: "Zimbra Collaboration Suite contains a request attribute override vulnerability caused by unauthenticated requests to /h/* populating servlet attributes, letting attackers execute JavaScript in another user's session combined with CVE-2026-10632, exploit requires attacker to supply valid token and document identifiers."
url: https://panop.io/threat-heartbeat/CVE-2026-50053/
---

# CVE-2026-50053 Zimbra Collaboration Suite - Stored XSS

Zimbra Collaboration Suite contains a request attribute override vulnerability caused by unauthenticated requests to /h/\* populating servlet attributes, letting attackers execute JavaScript in another user's session combined with CVE-2026-10632, exploit requires attacker to supply valid token and document identifiers.

CVSS base score 8.7 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.42% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-50053)

## Details

Type

Stored XSS

Impact

Client Script Exec

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

Published

23 October 2026

Updated

25 October 2026

Weakness

[CWE-642](https://cwe.mitre.org/data/definitions/642.html)

## Vendor fix

Update to version 10.1.17 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-50053](https://nvd.nist.gov/vuln/detail/CVE-2026-50053)
- [https://wiki.zimbra.com/wiki/Zimbra\_Security\_Advisories](https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories)
- [https://www.rapid7.com/blog/post/ve-breaking-zimbra-identity-boundaries-part-1/](https://www.rapid7.com/blog/post/ve-breaking-zimbra-identity-boundaries-part-1/)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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