Staff privilege escalation via unsanitized image captions
Published Aug 5, 2026 · Updated Aug 5, 2026
Stored XSS in Ghost 4.9.0 through 6.54.0 allows remote authenticated users to hijack another staff user's Admin session via a crafted caption. Ghost's frontend context preparation treated feature_image_caption as a Handlebars SafeString without sanitizing its HTML, and the Admin post-history preview rendered the same untrusted caption. Any staff account can store the payload, but another staff user must view affected content for script execution and session takeover.
Summary
What happened
Stored XSS in Ghost 4.9.0 through 6.54.0 allows remote authenticated users to hijack another staff user's Admin session via a crafted caption. Ghost's frontend context preparation treated feature_image_caption as a Handlebars SafeString without sanitizing its HTML, and the Admin post-history preview rendered the same untrusted caption. Any staff account can store the payload, but another staff user must view affected content for script execution and session takeover.
The record
- CVE
- CVE-2026-70596
- Published
- Aug 5, 2026
- Updated
- Aug 5, 2026
- Vendor
- Ghost Foundation
- Product
- Ghost
- Classifications
- CWE-79, T1059.007
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 5, 2026CVE publishedPublication date reported by the CVE source.
- Aug 5, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 4.9.0, < 6.54.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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