CVE-2026-63177Malcolm Vulnerable to Authorization Bypass via URI Normalization Differential in Nginx Lua RBAC
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 7.1 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
- Weakness (CWE)
- CWE-863
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Awaiting Analysis
- Record last updated
- Oct 2, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
cisagov Malcolm cisagov:malcolm (from the name) | before 26.07.0; 26.07.0 not affected | CNA record |
References
- https://github.com/cisagov/Malcolm/security/advisories/GHSA-m5fr-rv3h-xg2rx-refsource-confirm
- https://github.com/cisagov/Malcolm/releases/tag/v26.07.0x-refsource-misc
- https://www.cisa.gov/news-events/ics-advisories/icsa-26-230-01
- https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-230-01.json
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.