Privilege escalation in Minecanton209 Novumos
CVE-2026-40317
NovumOS is a custom 32-bit operating system written in Zig and x86 Assembly. In versions prior to 0.24, Syscall 12 (JumpToUser) accepts an arbitrary entry point address from user-space registers without validation, allowing any Ring 3 user-mode process to jump to kernel addresses and execute arbitrary code in Ring 0 context, resulting in local privilege escalation. This issue has been fixed in version 0.24. If developers are unable to immediately update, they should restrict syscall access by running the system in single-user mode without Ring 3, and disable user-mode processes by only running kernel shell with no user processes. This issue has been fixed in version 0.24.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
EPSS: 0.002 (13.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.3 (Critical). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.
Affected products
- Minecanton209 Novumos — versions < 0.24
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-40317?
- CVE-2026-40317 is a critical-severity vulnerability in Minecanton209 Novumos, classified under Improper Input Validation. CVSS score: 9.3/10. Published 2026-04-18.
- How severe is CVE-2026-40317?
- Critical severity. CVSS v3 base score is 9.3 out of 10.