Incorrect permission assignment for critical resource in baserCMS - #VU152767
Published: September 29, 2026
Vulnerability identifier: #VU152767
CSH Severity: Low
CVSS v4: 6.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-732
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to escalate privileges.
The vulnerability exists due to incorrect permission assignment for a critical resource in the bc-mcp plugin's OAuth2Service::generateKeyPair() function when generating the OAuth2 signing key pair. A local user can read the OAuth2 private key and re-sign an access token with altered user_id or scope claims to escalate privileges.
Exploitation requires access to a live, unexpired, and unrevoked token identifier.
Affected software
baserCMS
Remediation
Install security update from vendor's website.
baserCMS - update to 5.4.1