Malcolm Vulnerable to Authorization Bypass via URI Normalization Differential in Nginx Lua RBAC
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.
CVE-2026-63177
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-63177
Malcolm
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "cisagov",
"product": "Malcolm",
"versions": [
{
"status": "affected",
"version": "< 26.07.0"
},
{
"status": "unaffected",
"version": "26.07.0"
}
],
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-63177
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #8171 · Revision 1
- Added to Heist Feed
- Publisher date