CVE-2026-121458 (GCVE-0-2026-121458)
Vulnerability from cvelistv5 – Published: 2026-11-03 12:59 – Updated: 2026-11-03 18:31 X_Open Source
VLAI
EPSS
VEX
Title
Instatic before 0.0.21 Authorization Bypass via MCP Content Read Tools
Summary
Instatic before 0.0.21 contains a missing authorization vulnerability in its AI/MCP content read tools that allows low-privileged authenticated users with ai.chat and content.edit.own capabilities to access data rows belonging to other users by calling content_get_document and content_list_documents without the object-level authorization checks enforced by the normal HTTP API. Attackers can use the MCP interface to retrieve private or unpublished draft content and enumerate rows from the posts system table, resulting in cross-user data disclosure.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-11-03 17:23 UTC
CWE
- CWE-862 - Missing Authorization
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/CoreBunch/Instatic/security/ad… | vendor-advisorytechnical-description |
| https://github.com/CoreBunch/Instatic/releases/ta… | patchissue-tracking |
| https://www.vulncheck.com/advisories/instatic-bef… | third-party-advisory |
Impacted products
Date Public
2026-11-03 00:00
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