# CVE-2026-102143 — Kiteworks Email Protection Gateway

> As of 2026-10-01, CVE-2026-102143 is a HIGH-severity vulnerability in Kiteworks Email Protection Gateway, CVSS v3.1 7.5, EPSS 0.3% (22.9th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-102143, most recently “Kiteworks 9.5.1 Patches 126 Vulnerabilities Including Critical Account Takeover in Core and Email Protection Gateway (CVE-2026-102147, CVE-2026-102149)”.

**Last updated:** 2026-10-01

## What is CVE-2026-102143?

An unauthenticated attacker could cause a file with attacker-controlled content to be written to the appliance filesystem through an administrative upload handler that did not properly authenticate the request. This did not by itself result in code execution, which would require a separate vulnerability to place the file in an executable location.

The record classifies CVE-2026-102143 under weakness classes [CWE-306](https://intel.threadlinqs.com/cwe/CWE-306), [CWE-434](https://intel.threadlinqs.com/cwe/CWE-434). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on integrity. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 5 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7.5 — HIGH (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N`)
- **EPSS (FIRST):** 0.3% probability of exploitation in the next 30 days, higher than 22.9% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 4.7/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-09-30, last modified 2026-10-01

## Is CVE-2026-102143 being exploited?

No public exploitation evidence for CVE-2026-102143 is recorded in the sources Threadlinqs tracks — CISA KEV, Exploit-DB, public proof-of-concept repositories and ProjectDiscovery Nuclei — as of 2026-10-01. That is an absence of evidence in those feeds, not a guarantee that the vulnerability is unexploited.

## Affected products and versions

- [Kiteworks](https://intel.threadlinqs.com/vendors/kiteworks): Email Protection Gateway

## How to fix CVE-2026-102143

No vendor patch reference has been recorded for CVE-2026-102143 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-102143

1 tracked threat in the Threadlinqs corpus references CVE-2026-102143, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Kiteworks 9.5.1 Patches 126 Vulnerabilities Including Critical Account Takeover in Core and Email Protection Gateway (CVE-2026-102147, CVE-2026-102149)](https://intel.threadlinqs.com/threat/TL-2026-2902) — CRITICAL · 2026-10-02

## Sources

Enriched from CVE.org, NVD, FIRST EPSS. Last verified by Threadlinqs on 2026-10-05. This product uses the NVD API but is not endorsed or certified by the NVD.

**Third-party advisory**

- [raw.githubusercontent.com — third party advisory](https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/VA/white/2026/va-26-274-01.json)

**Other references**

- [github.com](https://github.com/kiteworks/security-advisories/security/advisories/GHSA-3p9g-jh62-8f89)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-102143
Full detection coverage and IOCs for threats exploiting CVE-2026-102143 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp