Vulnerability · Published Sep 11, 2026 · Assigned by icscert

CVE-2026-90452Improper certificate validation in Malcolm

Medium 5.3

In plain English

A medium-severity improper certificate validation in Malcolm from CISA. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 1% of all known vulnerabilities).

Severity (CVSS 3.1)5.3Medium

Exploit odds (30 days)<0.1%top 99.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
CISA	Malcolm	0 – before v26.06.0

Weakness: CWE-295 · Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

References

https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2026/icsa-26-254-01.json government-resource, vendor-advisory
https://www.cisa.gov/news-events/ics-advisories/icsa-26-254-01