---
id: CVE-2026-103276
title: >-
  Ghost versions before 6.20.0 contain a file extension filtering bypass
  vulnerability that allows unauthenticated attackers to read theme templates
  and metadata
summary: >-
  Ghost versions before 6.20.0 contain a file extension filtering bypass
  vulnerability that allows unauthenticated attackers to read theme templates
  and metadata. Attackers can use URL encoding to bypass extension validation
  and access sen…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'
cwe:
  - CWE-173
vendor: TryGhost
product: Ghost
affected:
  - Ghost < 6.20.0
published: '2026-10-01'
updated: '2026-10-01'
sourceUpdated: '2026-10-01T11:17:23.237'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-103276'
references:
  - url: 'https://github.com/TryGhost/Ghost/security/advisories/GHSA-6v8p-3jx9-8chr'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/ghost-before-6.20.0-file-read-via-url-encoding-bypass
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-10-01T11:42:53.810Z'
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-01T13:34:31.162544Z'
---

## Overview

Ghost versions before 6.20.0 contain a file extension filtering bypass vulnerability that allows unauthenticated attackers to read theme templates and metadata. Attackers can use URL encoding to bypass extension validation and access sensitive theme files.

## Remediation

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