CVE-2026-63177: Cisagov Malcolm

High severity, CVSS 7.1. EPSS: 0.4% chance of exploitation in the next 30 days.

Malcolm is a network traffic analysis tool suite. Prior to version 26.07.0, role-based access control enforced in the Nginx OpenResty Lua layer evaluates the raw, unnormalized `ngx.var.request_uri`, while Nginx itself routes requests using the normalized path. An authenticated low-privilege user can prepend a traversal segment (for example `/x/../upload/...`) so that Nginx routes the request to a restricted backend while the Lua role check fails to match any rule and falls open, granting access it should deny. Version 26.07.0 fixes the issue.

Affected products

• Cisagov Malcolm: before 26.07.0 (fixed in 26.07.0)

Published 2026-08-11. Last modified 2026-10-02.