CVE-2026-50053

Published Oct 23, 2026

Last updated 2 days ago

Overview

Description
A request attribute override vulnerability in Zimbra Collaboration Suite (ZCS) allows unauthenticated requests to /h/* to populate servlet attributes intended for trusted internal dispatch. RestFilter copies URL parameters specifying an authentication token, target account, target item and dispatch state into the request attributes consumed by the Classic Web Client. Combined with CVE-2026-10632 on ZCS 10.1.16, this allows an attacker to supply their own valid token and document identifiers and execute JavaScript in another user's signed-in browser session. ZCS 10.1.17 blocks that XSS chain by changing the document renderer, but retains the request attribute override.
Source
cve@rapid7.com
NVD status
Awaiting Analysis

Risk scores

CVSS 3.1

Type
Secondary
Base score
8.7
Impact score
5.8
Exploitability score
2.3
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
Severity
HIGH

Weaknesses

cve@rapid7.com
CWE-642

Social media

Hype score
Not currently trending