{"id":"CVE-2026-90447","title":"A routing rule selects between two different authentication mechanisms for the same downstream service based on the value of a client-supplied request header, rather than on any property the client cannot control","summary":"A routing rule selects between two different authentication mechanisms for the same downstream service based on the value of a client-supplied request header, rather than on any property the client cannot control. An authenticated user i…","severity":"medium","cvss":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","cwe":["CWE-290"],"vendor":"CISA","product":"Malcolm","affected":["Malcolm < v26.06.0"],"published":"2026-09-11","updated":"2026-10-02","sourceUpdated":"2026-10-02T22:16:55.190","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-90447","references":[{"url":"https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2026/icsa-26-254-01.json","label":"ics-cert@hq.dhs.gov"},{"url":"https://www.cisa.gov/news-events/ics-advisories/icsa-26-254-01","label":"ics-cert@hq.dhs.gov"}],"tags":["nvd","cve.org"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-14T16:14:01.854681Z"},"epss":0.0022,"epssPercentile":0.12484,"scores":{"nvd":6.5,"cna":7.1},"ingestedAt":"2026-09-14T11:11:19.875Z","slug":"CVE-2026-90447","body":"## Overview\n\nA routing rule selects between two different authentication mechanisms for the same downstream service based on the value of a client-supplied request header, rather than on any property the client cannot control. An authenticated user in possession of a shared service credential can set this header to route around the primary role-based authorization check and reach the alternate path's fixed, elevated role instead. This allows a low-privileged authenticated attacker who knows the shared credential to perform actions reserved for a higher-privileged role.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":36,"depthScoreParts":{"impact":35.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":215072,"id":"CVE-2026-90447","ts":1790980431428,"field":"cvss","old":"7.1","new":"6.5"},{"seq":215071,"id":"CVE-2026-90447","ts":1790980431428,"field":"severity","old":"high","new":"medium"}]}