HIGH 7.1 NVD
CVE-2026-121458
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.ch
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 Attackers can use the MCP interface to retrieve private or unpublished draft content and enumerate rows from the posts system table, resulting in cross-user data disclosure.
References
- https://github.com/CoreBunch/Instatic/releases/tag/v0.0.21
- https://github.com/CoreBunch/Instatic/security/advisories/GHSA-x5cc-8486-8qqx
- https://www.vulncheck.com/advisories/instatic-before-authorization-bypass-via-mcp-content-
This high severity vulnerability with a CVSS score of 7.1 was published on 2026-11-03 via NVD.
vulnfeed aggregates 18261 vulnerabilities from NVD, CISA KEV,
Ubuntu, Debian, Red Hat, Kubernetes, Exploit-DB, OSS-Security, GitHub and OpenStack — updated every 4 hours.