Vulnerability · Published Sep 11, 2026 · Assigned by icscert

CVE-2026-90451Use of Default Credentials in Malcolm

Medium 5.9

In plain English

A medium-severity security flaw 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 0.3% (higher than 17% of all known vulnerabilities).

Severity (CVSS 3.1)5.9Medium

Exploit odds (30 days)0.3%top 83.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

An example environment-configuration file ships with a fixed, publicly-known secret value used to sign authentication cookies for a bundled packet-analysis component. A deployment that copies this example file into active configuration without running the setup routine that regenerates the value will use the known default, allowing an attacker aware of the default to forge valid authentication cookies for that component.

Affected products (as reported)

Vendor	Product	Versions
CISA	Malcolm	0 – before v26.06.0

Weakness: CWE-1392 · Vector: CVSS:3.1/AV:N/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