CVE-2026-50053
HIGH
MEDIUM
Priority: 0.03
BB Relevance:
57/100
Published: 2026-10-23
Modified: 2026-10-28
First seen: 2026-10-29
Status: active
Attack Surface
Network
Low Complexity
Conf. Impact
Integ. Impact
Scope Change
CVSS Vector Breakdown
AV:
Network
AC:
Low
PR:
Low
UI:
Required
S:
Changed
C:
High
I:
High
A:
None
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.
Weakness Classification (1)
Affected Software (2)
| Vendor | Product | Version |
|---|---|---|
| Zimbra | Zimbra Collaboration Suite | 0 |
| Zimbra | Zimbra Collaboration Suite | 0 |