---
id: CVE-2026-88593
title: >-
  kkFileView 5.0.0 through 5.0.2 allows reflected XSS via the /onlinePreview
  endpoint
summary: >-
  kkFileView 5.0.0 through 5.0.2 allows reflected XSS via the /onlinePreview
  endpoint. The OnlinePreviewController passes the user-controlled page and
  kkagent request parameters to FreeMarker templates without sanitization, and
  the templat…
severity: medium
cvss: 6.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'
cwe:
  - CWE-79
published: '2026-09-16'
updated: '2026-09-22'
sourceUpdated: '2026-09-22T20:00:03.713'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-88593'
references:
  - url: 'https://github.com/sg-summer/cve/issues/3'
    label: cve@mitre.org
  - url: 'https://github.com/sg-summer/cve/issues/3'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
epss: 0.00196
epssPercentile: 0.09561
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-22T15:17:08.345053Z'
ingestedAt: '2026-09-16T18:01:17.452Z'
---

## Overview

kkFileView 5.0.0 through 5.0.2 allows reflected XSS via the /onlinePreview endpoint. The OnlinePreviewController passes the user-controlled page and kkagent request parameters to FreeMarker templates without sanitization, and the templates insert these values into raw JavaScript contexts.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.