CVE-2026-91851: MISP Dashboard Template ACL Bypass Due to VARCHAR-to-Integer Type Coercion in Permission Flag Comparison

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of 29 Oct 2026. If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?

0.4%

EPSS score, percentile 28.7 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

5.3 Medium

CVSS v4.0 base score, given by the CNA

What should I do?

The fix corrects the type mismatch in the permission flag comparison by replacing the integer literal 0 with the explicit string values '' and '0' … Full textSolution from the CVE record.

CISA has set no required action, because the vulnerability is not in KEV.

Advisories and patches (1)

Which versions are affected?

Affected

• before 2.5.46

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026; CVE List, as of 29 Oct 2026. About the data.

What to do

Solution (from the CVE record)

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.

Advisories and patches

• Security patch (Patch)

This summary is based on the CVE record as of 29 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

As listed in the CVE record.

Source: CVE List, as of 29 Oct 2026. About the data.

About this vulnerability

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 there…

Summary: CVE record, as of 29 Oct 2026.

• CISA has not added CVE-2026-91851 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
• The CVE record was published on 15 Sep 2026.
• The CVE record carries a CVSS v4.0 base score of 5.3 (Medium), given by its CNA.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.4% (percentile 28.7), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
• CISA's SSVC assessment in the CVE record: exploitation none, automatable no, technical impact partial.
• The credits in the CVE record name Anthropic (Claude) as finder.

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; CVE List, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026. About the data.

Description

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

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

Source: CVE List, as of 29 Oct 2026. About the data.

Timeline