What’s Vulnerable › Vulnerabilities

CVE-2026-19670: Incorrect Authorization in CISA Malcolm

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-18 · updated 2026-09-08
• Weakness: CWE-863

Description

Malcolm's nginx Lua role-based access control (RBAC) layer decides whether an authenticated user may reach a role-restricted path (e.g. /htadmin, /auth, /admin_login, /arkime/api/esadmin, NetBox, upload endpoints) by pattern-matching the raw, percent-encoded request URI. Nginx itself, however, selects which location block actually serves the request using the percent-decoded, normalized URI. Because the RBAC check never percent-decodes its input, an authenticated low-privilege user can request an admin-only path using percent-encoding (e.g. /%68tadmin.php) and have nginx route it to the restricted location while the Lua RBAC gate evaluating the un-decoded raw string finds no matching restriction and grants access.

Affected products

• cisagov Malcolm: through 26.07.1

References

• https://github.com/cisagov/Malcolm/security/advisories/GHSA-f2v6-8cj4-mhr6
• https://www.cisa.gov/news-events/ics-advisories/icsa-26-230-01
• https://github.com/cisagov/Malcolm/security/advisories/GHSA-f2v6-8cj4-mhr6

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