CVE-2026-103276

Medium

Description

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.

SeverityMedium

CVSS5.3

Exploit probability—

Product

Ghost

PublishedOct 1, 2026

First seenOct 1, 2026

Weakness typeCWE-173CWE-173

How to fix

Update

TryGhost Ghost6.20.0 or later

Vendor advisories

github.com/TryGhost/Ghost/security/advisories/GHSA-6v8p-3jx9-8chr

Affected products

Product	Affected versions	Fixed in
TryGhost Ghost	v < 6.20.0	6.20.0

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.