CVE-2026-91851 PUBLISHED

MISP Dashboard Template ACL Bypass Due to VARCHAR-to-Integer Type Coercion in Permission Flag Comparison

Assigner: CIRCL
Reserved: 15.09.2026 Published: 15.09.2026 Updated: 15.09.2026

Affected versions of MISP incorrectly filter dashboard templates that are restricted to a specific permission flag.

DashboardsController::listTemplates() allowed a template when either:

- its restrict_to_permission_flag matched one of the current user’s permission flags, or

- restrict_to_permission_flag equaled integer 0

However, restrict_to_permission_flag is a varchar. MySQL therefore performed numeric coercion when comparing the column against integer 0. Strings such as perm_site_admin convert numerically to zero, making expressions such as perm_site_admin = 0 evaluate true and causing the “unrestricted” branch to match permission-restricted templates as well.

Version affected: ≤2.5.45

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
CVSS Score: 5.3

Product Status

Vendor MISP
Product MISP
Versions
  • affected from 0 to 2.5.46 (excl.)

Solutions

The fix corrects the type mismatch in the permission flag comparison by replacing the integer literal 0 with the explicit string values '' and '0', which are the actual database values representing an unrestricted dashboard template. This ensures MySQL performs a proper string-to-string comparison, so only rows genuinely marked as unrestricted are returned, restoring the intended per-permission-level access control on dashboard templates.

Credits

  • iglocska remediation developer
  • Claude Opus 5 (1M context) remediation developer

References

Problem Types

  • CWE-863 Incorrect Authorization CWE
  • CWE-697 Incorrect Comparison CWE

Impacts

  • CAPEC-1 Accessing Functionality Not Properly Constrained by ACLs