CVE-2026-50053
Zimbra Collaboration Suite RestFilter Request Attribute Override via Unauthenticated URL Parameters
Fetching some sources has been requested. Reload in about a minute to see them.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
Attack conditions and impact
Derived from the CNA (via NVD) CVSS 3.1 vector| Metric | Value | Meaning |
|---|---|---|
| Attack vector AV | N | Network |
| Attack complexity AC | L | Low (easy) |
| Privileges required PR | L | Regular user |
| User interaction UI | R | Required |
| Scope S | C | Changed (affects other components) |
| Confidentiality C | H | High |
| Integrity I | H | High |
| Availability A | N | None |
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
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.
CVSS assessments
| Provider | Version | Score | Vector |
|---|---|---|---|
| NVD / [email protected] (Secondary) | 3.1 | 8.7 HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N |
| CNA / rapid7 | 3.1 | 8.7 HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N |
Affected products and packages
CNA (CVE.org)
| Vendor | Product | Versions |
|---|---|---|
| Zimbra | Zimbra Collaboration Suite | affected: 0 … <= 10.1.17 default: unaffected |
Linux distribution status
References (2)
- https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories NVD, CNA vendor-advisory
- https://www.rapid7.com/blog/post/ve-breaking-zimbra-identity-boundaries-part-1/ NVD, CNA related