CVE-2026-103276: Improper Handling of Alternate Encoding in TryGhost Ghost
Ghost versions before 6.20.0 contain a file extension filtering bypass vulnerability that allows unauthenticated attackers to read theme templates and metadata. Attackers can use URL encoding to bypass extension validation and access sensitive theme files.
AI Analysis
Technical Summary
CVE-2026-103276 describes a file extension filtering bypass vulnerability in TryGhost Ghost versions prior to 6.20.0. The flaw allows unauthenticated attackers to use alternate URL encoding to circumvent extension validation controls and access sensitive theme template and metadata files. This could expose internal theme data that is not intended for public access.
Potential Impact
An attacker can read sensitive theme files without authentication by exploiting the bypass in file extension filtering. This may lead to disclosure of proprietary or sensitive theme information but does not involve code execution or privilege escalation according to the available data.
Mitigation Recommendations
Upgrade to Ghost version 6.20.0 or later where this vulnerability is fixed. Since the vulnerability is patched in 6.20.0, applying this official fix fully mitigates the issue.
CVE-2026-103276: Improper Handling of Alternate Encoding in TryGhost Ghost
Description
Ghost versions before 6.20.0 contain a file extension filtering bypass vulnerability that allows unauthenticated attackers to read theme templates and metadata. Attackers can use URL encoding to bypass extension validation and access sensitive theme files.
CVSS v4.0
Score 6.9medium
Affected software
TryGhost
Ghost
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-103276 describes a file extension filtering bypass vulnerability in TryGhost Ghost versions prior to 6.20.0. The flaw allows unauthenticated attackers to use alternate URL encoding to circumvent extension validation controls and access sensitive theme template and metadata files. This could expose internal theme data that is not intended for public access.
Potential Impact
An attacker can read sensitive theme files without authentication by exploiting the bypass in file extension filtering. This may lead to disclosure of proprietary or sensitive theme information but does not involve code execution or privilege escalation according to the available data.
Mitigation Recommendations
Upgrade to Ghost version 6.20.0 or later where this vulnerability is fixed. Since the vulnerability is patched in 6.20.0, applying this official fix fully mitigates the issue.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-09-30T10:59:00.638Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6abe7486a43b0b3b89bd1c49
Added to database: 10/01/2026, 14:56:06 UTC
Last enriched: 10/01/2026, 15:15:41 UTC
Last updated: 10/01/2026, 22:26:14 UTC
Views: 3
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