CVE-2026-104411 TryGhost CVE debrief

Who should care

Defenders responsible for Ghost installations, particularly those using the default local storage adapter, should assess exposure and prioritize updating to version 6.64.0 or later.

Why it matters

Defenders should prioritize updating Ghost installations to version 6.64.0 or later, and verify that file uploads are properly restricted and served with the correct content type, as a stored XSS vulnerability could be used to host scripts on the site's domain, possibly resulting in compromise of other staff users' admin sessions.

• Possible compromise of staff users' admin sessions
• Hosting scripts on the site's domain
• Verification of file upload restrictions and content type serving
• Updating Ghost installations to version 6.64.0 or later

Technical summary

A stored XSS vulnerability in Ghost could be used to host scripts on the site's domain, possibly resulting in compromise of other staff users' admin sessions. The vulnerability is present in Ghost from v6.22.1 up to v6.64.0. Defenders should prioritize updating Ghost installations to version 6.64.0 or later, and verify that file uploads are properly restricted and served with the correct content type. This vulnerability restricts the content type that uploaded files are served with, to prevent browsers from executing them. On sites using the default local storage adapter, this restriction was not applied, so files uploaded by any staff user were served with a content type derived from their file extension.

Defensive priority

Defenders should prioritize updating Ghost installations to version 6.64.0 or later, and verify that file uploads are properly restricted and served with the correct content type.

Recommended defensive actions

• Update Ghost installations to version 6.64.0 or later
• Verify that file uploads are properly restricted and served with the correct content type
• Monitor for suspicious file uploads and admin session activity
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and source item provide details on a stored XSS vulnerability in Ghost, which could be used to host scripts on the site's domain, possibly resulting in compromise of other staff users' admin sessions.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.