CVE-2026-90447
mediumpriority · track · 0EPSS 0.002 · 12 %ileUSEPSS · scored 2026-10-27
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 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.
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
A vendor fix is available.
- FixedMalcolmcisa_csaf_ot
The latest version of Malcolm (September 2026 or later) fixes these vulnerabilities. Affected users are encouraged to update their instance of Malcolm to the latest version.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4.9–7.1
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (1)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- ICSA-26-254-01CISA Malcolm2026-09-11icsa · cisa_csaf_otUS
CISA recommends users take defensive measures to minimize the risk of exploitation of these vulnerabilities.
sources
Which sources assert this record, and when.
references (2) nvd
External citations — patches, advisories, analysis.
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