Self-hosted Ghost instances have been flagged for a critical cross-site scripting (XSS) vulnerability that affects certain Docker deployment setups. Users must act immediately to secure their blogs and publications.
Problem
A recently disclosed XSS flaw allows malicious input to run unsafe scripts in the Ghost admin or frontend under specific configurations. This issue is amplified for Ghost instances deployed with outdated or unofficial Docker images (“second-class Docker support”) that lag behind official releases in applying sanitization and security fixes.
The vulnerability was reported in the official Ghost forum and GitHub Docker library, highlighting the risk to self-hosters who do not follow timely updates.
Email Alert Received
Many Ghost self-hosters have received the following critical notification:
Action required: Critical alert from Ghost instance https://example.com/
Update Ghost now: your Ghost site is vulnerable to an attack that lets unauthenticated attackers read arbitrary data from the database.
This alert indicates a serious security vulnerability that requires immediate attention.
If you don't have such mail probably you are not impacted or don't have working mail settings.
Solution
To mitigate the risk:
- Update Ghost to the latest patched version (Ghost 6.x security updates have been released).
- Use official Docker images maintained by the Ghost project, not community forks.
- Rebuild and redeploy your Docker containers after update.
- Test your instance in a staging environment before production rollout.
Keeping your deployment current ensures that all known XSS patches and sanitization updates are applied.
FAQ
Q: Who is impacted?
Any self-hosted Ghost instance, especially those using unofficial or out-of-date Docker images, is potentially vulnerable.
Q: How severe is this?
This is a critical XSS vulnerability that can allow script injection and session compromise in admin or public views.
Q: What needs to be done right now?
Update to the latest Ghost 6.x release and use official Docker images. Rebuild and redeploy your containers promptly.
Q: What if I can’t update immediately?
Restrict admin access, enforce HTTPS, and limit public post submissions until you can apply the patch.