# CVE-2026-103266: Ghost unauthenticated member modification and HTML injection in newsletters

Source: https://junglewise.ai/threats/cve-2026-103266-ghost-versions-5-2-0-through-versions-prior-to-6-62-0-allow-a  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-01. Updated: 2026-10-05  
License: CC BY 4.0 with a link back

CVE-2026-103266 · Severity: high · CVSS 7.1 · Published 2026-10-01

Ghost is a blogging and newsletter platform that manages member accounts and email subscriptions. An attacker can exploit a flaw in the Stripe payment checkout process to modify member names, attach paid subscriptions without authorization, and inject malicious content into newsletters that may execute as HTML or JavaScript in recipients' email clients, potentially compromising member data and email security.

Technologies: [Ghost](https://junglewise.ai/threats/technologies/ghost-ghost). Vendors: [Ghost](https://junglewise.ai/threats/vendors/ghost).

## Quick answers

**Is CVE-2026-103266 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-103266 being exploited in the wild.

**How severe is CVE-2026-103266?** High severity, with a CVSS score of 7.1, published 1 October 2026.

**Which products and versions are affected?** Ghost 5.2.0 through 6.61.x.

**Is there a fix for CVE-2026-103266?** Yes: fixed in 6.62.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-103266 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-103266?** Check whether you run Ghost at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 6.62.0

## Technical details

An authorization bypass in Ghost's Stripe Checkout flow allows unauthenticated attackers to modify member profile data (including name) and inject content into newsletters. The vulnerability requires user interaction (UI:R) and affects newsletter content delivery, resulting in potential XSS or HTML injection depending on email client rendering. The attack exploits incorrect authorization checks (CWE-863) during the payment checkout process for existing members.

## Affected products

- Ghost Ghost 5.2.0 through 6.61.x

## Timeline

- 2026-10-01: disclosed
- 2026-09-03: advisory: GitHub security advisory published

## References

- [https://github.com/TryGhost/Ghost/security/advisories/GHSA-qppx-rw6v-xjqf](https://github.com/TryGhost/Ghost/security/advisories/GHSA-qppx-rw6v-xjqf)
- [https://www.vulncheck.com/advisories/ghost-5.2.0-before-6.62.0-unauthenticated-stripe-checkout-account-modification](https://www.vulncheck.com/advisories/ghost-5.2.0-before-6.62.0-unauthenticated-stripe-checkout-account-modification)

## Related threats

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