---
id: CVE-2020-27509
title: >-
  Persistent XSS in Galaxkey Secure Mail Client in Galaxkey up to 5.6.11.5
  allows an attacker to perform an account takeover by intercepting the HTTP
  Post request when sending an email and injecting a specially crafted XSS
  payload in the '…
summary: >-
  Persistent XSS in Galaxkey Secure Mail Client in Galaxkey up to 5.6.11.5
  allows an attacker to perform an account takeover by intercepting the HTTP
  Post request when sending an email and injecting a specially crafted XSS
  payload in the '…
severity: medium
cvss: 5.4
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N'
cwe:
  - CWE-79
vendor: galaxkey
product: galaxkey
affected:
  - galaxkey < 5.6.11.5
patched:
  - galaxkey 5.6.11.5
published: '2022-06-26'
updated: '2026-07-05'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2020-27509'
references:
  - url: >-
      https://medium.com/@tomhulme_74888/persistent-cross-site-scripting-leading-to-full-account-takeover-on-galaxkey-v5-6-11-4-8bf96be35b54
    label: cve@mitre.org
  - url: 'http://galaxkey.com'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://medium.com/%40tomhulme_74888/persistent-cross-site-scripting-leading-to-full-account-takeover-on-galaxkey-v5-6-11-4-8bf96be35b54
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00579
epssPercentile: 0.45418
ingestedAt: '2026-07-06T17:03:24.788Z'
---

## Overview

Persistent XSS in Galaxkey Secure Mail Client in Galaxkey up to 5.6.11.5 allows an attacker to perform an account takeover by intercepting the HTTP Post request when sending an email and injecting a specially crafted XSS payload in the 'subject' field. The payload executes when the recipient logs into their mailbox.

## Affected

- `galaxkey < 5.6.11.5`

## Remediation

Upgrade past the affected range:

- `galaxkey 5.6.11.5`