CVE-2026-23408

/* * PoC Concept for CVE-2026-23408 * This is a conceptual demonstration of the logic flow. * Exploiting this requires specific kernel memory layout manipulation. */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/socket.h> #include <linux/netlink.h> // Mock structures to represent the kernel logic interaction // In a real scenario, this interacts with AppArmor netlink interface. struct aa_load_ent { char *ns_name; // other fields... }; void trigger_vulnerability_concept() { printf("[+] Attempting to trigger AppArmor double free...\n"); // 1. Prepare data where unpack returns NULL for ns_name initially // 2. Ensure ent->ns_name is set to a valid heap pointer struct aa_load_ent *ent = malloc(sizeof(struct aa_load_ent)); ent->ns_name = strdup("target_namespace"); char *ns_name = NULL; // Simulation of kernel code path: // error = aa_unpack(udata, &lh, &ns_name); // Assume ns_name remains NULL if (ns_name == NULL && ent->ns_name) { ns_name = ent->ns_name; // VULNERABILITY: Missing ent->ns_name = NULL; printf("[+] ns_name assigned from ent->ns_name: %p\n", ns_name); } // Simulation of aa_load_ent_free(ent) printf("[-] Freeing ent (frees ent->ns_name at %p)\n", ent->ns_name); free(ent->ns_name); free(ent); // Simulation of final kfree(ns_name) printf("[-] Freeing ns_name again (Double Free at %p)\n", ns_name); free(ns_name); // CRASH: Double Free printf("[!] If kernel panicked, exploitation successful.\n"); } int main() { // Note: Actual exploitation requires calling kernel syscalls/netlink // to reach aa_replace_profiles(). This code illustrates the C logic flaw. trigger_vulnerability_concept(); return 0; }

{"cve": {"id": "CVE-2026-23408", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-04-01T09:16:16.747", "lastModified": "2026-04-24T15:24:02.493", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\napparmor: Fix double free of ns_name in aa_replace_profiles()\n\nif ns_name is NULL after\n1071 error = aa_unpack(udata, &lh, &ns_name);\n\nand if ent->ns_name contains an ns_name in\n1089 } else if (ent->ns_name) {\n\nthen ns_name is assigned the ent->ns_name\n1095 ns_name = ent->ns_name;\n\nhowever ent->ns_name is freed at\n1262 aa_load_ent_free(ent);\n\nand then again when freeing ns_name at\n1270 kfree(ns_name);\n\nFix this by NULLing out ent->ns_name after it is transferred to ns_name\n\n\")"}], "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-415"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5.1", "versionEndExcluding": "5.10.253", "matchCriteriaId": "45E871E1-B00E-4E88-83A3-60B38EAF2B8A"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "5.15.203", "matchCriteriaId": "20DDB3E9-AABF-4107-ADB0-5362AA067045"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.1.169", "matchCriteriaId": "DBEC0E5D-641C-4E98-A6D9-5799B10CE451"}, {"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": "6.12.77", "matchCriteriaId": "B3D12E00-E42D-4056-B354-BAD4903C03A5"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.18", "matchCriteriaId": "346AD1FB-0CE8-4D9D-8E56-5EB1A4D06199"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.8", "matchCriteriaId": "C65A7D85-C7C6-485E-AC35-66A374C73FAC"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:5.5:-:*:*:*:*:*:*", "matchCriteriaId": "EE98F46A-F7D9-4609-B6A0-882E7F0D378C"}, {"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/18b5233e860c294a847ee07869d93c0b8673a54b", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/35f4caec1352054b9a61cfdf2bf1898073637aa0", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["P ... (truncated)