# CVE-2026-121624: Nanosystems Supremo before 5.0.2.3874 Improper TLS Certificate Validation

Status: published. Published: 2026-11-03. Updated: 2026-11-03.

Nanosystems Supremo for Windows and macOS before 5.0.2.3874 contains an improper certificate validation vulnerability that allows adjacent attackers to intercept TLS connections by presenting untrusted certificates. Attackers on the same network can terminate and relay the client's TLS session using self-signed certificates to read usernames, SHA-256 password hashes, and license codes.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Nanosystems / Supremo: ≥ 0; < 5.0.2.3874 (affected, custom). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 7.6 (high); CVSS:4.0/AV:A/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 6.8 (medium); CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N; source: CNA: VulnCheck

- CVSS 4.0: 7.6 (high); CVSS:4.0/AV:A/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X; source: NVD: disclosure@vulncheck.com

- CVSS 3.1: 6.8 (medium); CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N; source: NVD: disclosure@vulncheck.com

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-295

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://pusi77.eu.org/blog/2026-11-03-supremo-tls-cve (CNA: VulnCheck; technical-description)

- https://www.supremocontrol.com/changelog/ (CNA: VulnCheck; release-notes)

- https://www.supremocontrol.com/ (CNA: VulnCheck; product)

- https://www.vulncheck.com/advisories/nanosystems-supremo-before-5.0.2.3874-improper-tls-certificate-validation (CNA: VulnCheck; third-party-advisory)

- https://pusi77.eu.org/blog/2026-11-03-supremo-tls-cve (disclosure@vulncheck.com)

- https://www.supremocontrol.com/ (disclosure@vulncheck.com)

- https://www.supremocontrol.com/changelog/ (disclosure@vulncheck.com)

- https://www.vulncheck.com/advisories/nanosystems-supremo-before-5.0.2.3874-improper-tls-certificate-validation (disclosure@vulncheck.com)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-121624; retrieved 2026-11-03; source updated 2026-11-03

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-121624; retrieved 2026-11-04; source updated 2026-11-03

Revision: 485629954695de86ecbb7cdbd698810ac8f3f334efcea4aa187352ead2e534b1

Canonical: https://y2.dev/cve/CVE-2026-121624

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