Auth bypass in Cisa Malcolm
CVE-2026-90454
A deployment mode intended to expose only read access to a bundled packet-analysis component's interface denies a list of write-capable routes by pattern, but the pattern omits routes that modify tags attached to stored session records, and the proxy configuration otherwise permits the request method those routes use. This allows an authenticated user on a deployment intended to be read-only to add or remove tags on stored session records.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.002 (4.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 5th percentile — 4.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.002 · change: -0.002
Affected products
Weakness classification (CWE)
References
- raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2026/icsa-26… (vendor-advisory, government-resource)
- www.cisa.gov/news-events/ics-advisories/icsa-26-254-01
Frequently asked questions
- What is CVE-2026-90454?
- CVE-2026-90454 is a medium-severity vulnerability in Cisa Malcolm, classified under Missing Authorization. CVSS score: 4.3/10. Published 2026-09-11.
- How severe is CVE-2026-90454?
- Medium severity. CVSS v3 base score is 4.3 out of 10.