CVE-2026-43240

/* * PoC Concept: Trigger kernel panic via kexec with memory limit. * Requires root privileges to perform kexec. */ #include <stdio.h> #include <stdlib.h> #include <unistd.h> int main() { // This is a conceptual representation. // In a real scenario, an attacker would load a kernel with kexec // using a restricted memory map (e.g., kexec -l --command-line='mem=512M' ...). printf("Simulating kexec load with memory restriction...\n"); // Command to trigger the vulnerability (requires root): // kexec -l /boot/vmlinuz --command-line="mem=512M" --initrd=/boot/initrd.img // kexec -e // The second kernel will panic when trying to access the IMA buffer // located outside the 512MB limit. return 0; }

{"cve": {"id": "CVE-2026-43240", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-06T12:16:44.330", "lastModified": "2026-05-11T14:27:36.347", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/kexec: add a sanity check on previous kernel's ima kexec buffer\n\nWhen the second-stage kernel is booted via kexec with a limiting command\nline such as \"mem=<size>\", the physical range that contains the carried\nover IMA measurement list may fall outside the truncated RAM leading to a\nkernel panic.\n\n BUG: unable to handle page fault for address: ffff97793ff47000\n RIP: ima_restore_measurement_list+0xdc/0x45a\n #PF: error_code(0x0000) – not-present page\n\nOther architectures already validate the range with page_is_ram(), as done\nin commit cbf9c4b9617b (\"of: check previous kernel's ima-kexec-buffer\nagainst memory bounds\") do a similar check on x86.\n\nWithout carrying the measurement list across kexec, the attestation\nwould fail."}], "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": "6.0", "versionEndExcluding": "6.1.165", "matchCriteriaId": "CCAEAB8E-BC62-4F74-ABC0-E38788A92B8B"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.6.128", "matchCriteriaId": "851E9353-6C09-4CC9-877E-E09DB164A3C2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.75", "matchCriteriaId": "BCE16369-98ED-41CF-8995-DFDC10B288D2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.16", "matchCriteriaId": "B4B8CDA9-BADF-4CF5-8B3B-702DE8EEA40B"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.6", "matchCriteriaId": "373EEEDA-FAA1-4FB4-B6ED-DB4DD99DBE67"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/22e460b6333a5f818b042ac89201f8e735556f4a", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/37f18915a261afe84dab462624ed829cddb77a9b", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/4d7a8f5f28187e3d2958b2a134473da2665207e7", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/c5489d04337b47e93c0623e8145fcba3f5739efd", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/d4a132f121c591b60dbaf57ea91f1faf11631fbc", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/f8f73bf0f8a57ee9b86792456bd42079bc98c6b7", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}