Summary
Ghost vulnerable to XSS via malicious Portal preview links
Vulnerable versions
This vulnerability is present in Ghost versions:
- v5.43.0 to v5.120.4
- v6.0.0 to v6.14.0
As well as in Portal versions:
- v2.29.1 to v2.51.4
- v2.52.0 to v2.57.0
References
Ghost thanks Younes Belalia for discovering and disclosing this vulnerability responsibly.
For more information
If users have any questions or comments about this advisory, email Ghost at [email protected].
Impact
An attacker was able to craft a malicious link that, when accessed by an authenticated staff user or member, would execute JavaScript with the victim's permissions, potentially leading to account takeover.
Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.
CVE-2026-24778 has a CVSS score of 8.8 (High). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (5.121.0, 2.51.5, 2.57.1, 6.15.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Ghost automatically loads the latest patch of the members Portal component via CDN. Therefore:
- For Ghost 5.x users, upgrading to v5.121.0 or later fixes the vulnerability (loads Portal v2.51.5, which contains the patch)
- For Ghost 6.x users, upgrading to v6.15.0 or later fixes the vulnerability (loads Portal v2.57.1, which contains the patch)
For Ghost installations using a customised or self-hosted version of Portal, it will be necessary to manually rebuild from or update to the latest patch version.
Frequently Asked Questions
- What is CVE-2026-24778? CVE-2026-24778 is a high-severity cross-site scripting (XSS) vulnerability in ghost (npm), affecting versions >= 5.43.0, < 5.121.0. It is fixed in 5.121.0, 2.51.5, 2.57.1, 6.15.0. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
- How severe is CVE-2026-24778? CVE-2026-24778 has a CVSS score of 8.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which packages are affected by CVE-2026-24778?
ghost(npm) (versions >= 5.43.0, < 5.121.0)@tryghost/portal(npm) (versions >= 2.29.1, < 2.51.5)
- Is there a fix for CVE-2026-24778? Yes. CVE-2026-24778 is fixed in 5.121.0, 2.51.5, 2.57.1, 6.15.0. Upgrade to this version or later.
- Is CVE-2026-24778 exploitable, and should I be worried? Whether CVE-2026-24778 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-24778 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-24778?
- Upgrade
ghostto 5.121.0 or later - Upgrade
@tryghost/portalto 2.51.5 or later - Upgrade
@tryghost/portalto 2.57.1 or later - Upgrade
ghostto 6.15.0 or later
- Upgrade