Skip to content

Paid gift memberships obtainable at minimal cost via the donations feature

Moderate
lsinger published GHSA-xm43-3m56-w3wf Jun 23, 2026

Package

npm ghost (npm)

Affected versions

>= 6.27.0 <= 6.43.1

Patched versions

6.44.0

Description

Impact

A vulnerability in Ghost's public donation checkout flow allowed an unauthenticated attacker to obtain full paid gift memberships for a minimal payment. No customer or member data was exposed, and the issue could not be used to steal money from a site or its members.

Vulnerable versions

This vulnerability is present in Ghost from v6.27.0 up to v6.43.1.

Patches

v6.44.0 contains a fix for this issue.

How to update

For self-hosters using Docker, find Docker’s official Ghost image on Docker Hub and follow the documentation on updating a Docker-based Ghost instance.

For self-hosters using Ghost-CLI, see the documentation for updating Ghost to the latest version.

Workarounds

If upgrading immediately is not possible, you can remove the vulnerable checkout path by disabling the donations feature in Ghost Admin under Settings → Membership → Tips & donations until the upgrade is applied.

References

We thank sane100400 and p4p3r for disclosing this vulnerability responsibly.

For more information

If you have any questions or comments about this advisory, email us at security@ghost.org.

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVE ID

CVE-2026-59817

Weaknesses

External Control of Assumed-Immutable Web Parameter

The web application does not sufficiently verify inputs that are assumed to be immutable but are actually externally controllable, such as hidden form fields. Learn more on MITRE.

Authorization Bypass Through User-Controlled Key

The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. Learn more on MITRE.

Credits