CVE-2026-105648: Ghost: Private IP Filtering Bypass via IPv6 Transition Addresses
Impact
A validation issue allowed some functionality, such as Webmentions, to be abused by an unauthenticated user to make limited HTTP requests to hosts in the Ghost server's internal network on some network configurations. A successful attack would not result in any response data being returned.
Vulnerable versions
This vulnerability is present in Ghost from v6.0.9 up to v6.64.0.
Patches
v6.65.0 contains a fix for this issue.
How to update
For self-hosters using Docker, find Docker's official Ghost image here. Updating a Docker-based Ghost instance is documented here.
If your Ghost is a Ghost-CLI install see our documentation on updating it to the latest version here.
References
Ghost thanks Nhat Anh Vu for disclosing this vulnerability responsibly.
For more information
If you have any questions or comments about this advisory, email us at security@ghost.org.
Other sources
Ghost is a Node.js content management system. From 6.0.9 until 6.65.0, a validation issue allowed some functionality, such as Webmentions, to be abused by an unauthenticated user to make limited HTTP requests to hosts in the Ghost server's internal network on some network configurations. A successful attack would not result in any response data being returned. This issue is fixed in version 6.65.0.
— NVD
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
npm/ghostto a version that resolves this vulnerability.Fixed in 6.65.0 - Upgrade
Upgrade
Ghostto a version that resolves this vulnerability.Fixed in 6.65.0
Event History
Frequently Asked Questions
Which deployments are exposed?
Ghost versions from 6.0.9 through 6.65.0 are affected, but exploitation depends on the server's network configuration and the availability of functionality such as Webmentions.
What does an attacker need to exploit this issue?
An attacker does not need authentication or user interaction. Exploitation requires crafting requests that bypass private-IP filtering through IPv6 transition addresses.
What is the practical impact of a successful attack?
An attacker can cause limited HTTP requests to hosts on the Ghost server's internal network. Response data is not returned to the attacker.
How can this be remediated?
Upgrade Ghost to version 6.65.0, which fixes the validation issue.