CVE-2026-40317

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{"affected": [{"affectedData": [{"product": "NovumOS", "vendor": "MinecAnton209", "versions": [{"status": "affected", "version": "< 0.24"}]}], "source": "security-advisories@github.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:minecanton209:novumos:*:*:*:*:*:*:*:*", "matchCriteriaId": "A40C9D50-FA65-41F9-859B-D8C31D3E55AC", "versionEndExcluding": "0.24", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}, {"lang": "es", "value": "NovumOS es un sistema operativo personalizado de 32 bits escrito en Zig y Ensamblador x86. En versiones anteriores a la 0.24, la llamada al sistema 12 (JumpToUser) acepta una direcci\u00f3n de punto de entrada arbitraria de los registros del espacio de usuario sin validaci\u00f3n, permitiendo que cualquier proceso en modo de usuario de Anillo 3 salte a direcciones del kernel y ejecute c\u00f3digo arbitrario en contexto de Anillo 0, lo que resulta en una escalada de privilegios local. Este problema ha sido solucionado en la versi\u00f3n 0.24. Si los desarrolladores no pueden actualizar inmediatamente, deben restringir el acceso a las llamadas al sistema ejecutando el sistema en modo de usuario \u00fanico sin Anillo 3, y deshabilitar los procesos en modo de usuario ejecutando solo el shell del kernel sin procesos de usuario. Este problema ha sido solucionado en la versi\u00f3n 0.24."}], "id": "CVE-2026-40317", "lastModified": "2026-10-26T21:10:00.170", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 9.3, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.5, "impactScore": 6.0, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-40317", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-04-20T15:26:18.306426Z", "version": "2.0.3"}}]}, "published": "2026-04-18T01:16:19.380", "references": [{"source": "security-advisories@github.com", "tags": ["Release Notes"], "url": "https://github.com/MinecAnton209/NovumOS/releases/tag/v0.24"}, {"source": "security-advisories@github.com", "tags": ["Exploit", "Vendor Advisory"], "url": "https://github.com/MinecAnton209/NovumOS/security/advisories/GHSA-xjx3-gjh9-45fm"}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory"], "url": "https://github.com/MinecAnton209/NovumOS/security/advisories/GHSA-xjx3-gjh9-45fm"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-20"}, {"lang": "en", "value": "CWE-269"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,0.24)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "cna", "scores": [{"score": 100.0, "source": "cna"}]}, "original": {"product": "NovumOS", "source": "cna", "vendor": "MinecAnton209"}, "product": "novumos", "vendor": "minecanton209"}], "analysis": {"en": {"generated_at": "2026-04-18T08:42:49.847539+00:00", "value": {"mitigation_remediation": ["Upgrade NovumOS to version 0.24 or later to apply the vendor's fix.", "If an upgrade is not immediately possible, run the system in single\u2011user mode to eliminate Ring\u202f3 processes, thereby preventing the exploit.", "Alternatively, disable user\u2011mode processes by running only the kernel shell and no user applications.", "In environments where upgrading or mode changes are infeasible, restrict access to Syscall\u202f12 by disabling or sandboxing user\u2011mode invocations of privileged operations."], "summary": {"action": "Immediate Patch", "impact": "Local Privilege Escalation"}, "threat_synthesis": {"affected_systems": "The affected vendor is MinecAnton209, publisher of NovumOS. Versions prior to\u202f0.24 are vulnerable. The operating system runs on 32\u2011bit x86 hardware and is intended for specialized embedded or experimental deployments. Any installation that still uses the pre\u20110.24 code base is exposed.", "description_and_impact": "NovumOS, a custom 32\u2011bit operating system written in Zig and x86 assembly, was found to allow any user\u2011mode (Ring\u202f3) process to execute code with kernel privileges by exploiting Syscall\u202f12 (JumpToUser). The syscall accepts an arbitrary entry point address from user\u2011space registers without validation, enabling the attacker to redirect program flow to arbitrary kernel addresses. This results in local privilege escalation and full system compromise. The flaw is rooted in improper input validation (CWE\u201120) and privileged access enforcement (CWE\u2011269).", "risk_and_exploitability": "The CVSS score of 9.4 categorizes this flaw as critical. Because it is a local privilege escalation without network or remote code execution vectors, the EPSS score is unavailable, and the vulnerability is not yet listed in CISA\u2019s KEV catalog. Attackers with access to a user\u2011level process or the ability to execute code in user mode can manually trigger Syscall\u202f12 with a crafted entry address, thereby jumping to the kernel and achieving arbitrary code execution in Ring\u202f0. There are no publicly documented constraints beyond the existence of a user/process in the system; the vulnerability can be exploited by any Ring\u202f3 program that can control its registers."}}}}, "created": "2026-04-18T08:45:41.385257+00:00", "updated": "2026-04-20T14:58:59.964131+00:00", "vendors": ["minecanton209", "minecanton209$PRODUCT$novumos"]}