Vulnerability in Cisa Malcolm
CVE-2026-90452
Requests from the reverse proxy to the identity-provider service for token discovery, introspection, and credential exchange do not verify the identity provider's server certificate. An attacker positioned on the network path between the proxy and the identity provider could impersonate the identity provider and issue forged authentication tokens accepted by the deployment.
Vulnerability class: Improper Certificate Validation
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.001 (0.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 1st percentile — 0.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: -0.000
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-2026-90452?
- CVE-2026-90452 is a medium-severity vulnerability in Cisa Malcolm, classified under Improper Certificate Validation. CVSS score: 5.3/10. Published 2026-09-11.
- How severe is CVE-2026-90452?
- Medium severity. CVSS v3 base score is 5.3 out of 10.