CVE-2026-31543

#!/bin/bash # PoC for CVE-2026-31543: Check for dm-crypt key leakage in kernel logs # This script demonstrates checking kernel logs for exposed key bytes. # Check if we have permission to read kernel logs (usually requires root or unprivileged_userns_clone=0 + kernel.dmesg_restrict=0) if [ -r /proc/kmsg ] || [ -r /var/log/kern.log ] || dmesg >/dev/null 2>&1; then echo "[*] Checking kernel logs for potential dm-crypt key leakage..." # Search for patterns related to key logging in the vulnerable function dmesg | grep -i "key" | head -n 5 echo "[!] If hex strings or key data appear above alongside 'read_key_from_user_keying', the system may be vulnerable." else echo "[-] Permission denied: Cannot read kernel logs to verify vulnerability." fi

{"cve": {"id": "CVE-2026-31543", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-04-24T15:16:28.350", "lastModified": "2026-04-28T18:46:51.353", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrash_dump: don't log dm-crypt key bytes in read_key_from_user_keying\n\nWhen debug logging is enabled, read_key_from_user_keying() logs the first\n8 bytes of the key payload and partially exposes the dm-crypt key. Stop\nlogging any key bytes."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16", "versionEndExcluding": "6.18.20", "matchCriteriaId": "1C570CE1-BC61-4BE6-9393-FD0CA8637367"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.10", "matchCriteriaId": "96D34333-38BE-4414-9E79-6EB764329581"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*", "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/36f46b0e36892eba08978eef7502ff3c94ddba77", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/4897bd307ba8757c31a3325ba6730961be606016", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/ed8d91f469845d62d44c565a55d2ab1767969357", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}