{"id":"CVE-2026-23415","title":"futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nfutex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()\n\nDuring futex_key_to_node_opt() execution, vma->vm_policy is read under\nspeculative mmap lock an…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= c042c505210dc3453f378df432c10fff3d471bc5 < 853f70c67d1b37e368fdcb3e328c4b8c04f53ac0","Linux >= c042c505210dc3453f378df432c10fff3d471bc5 < 7e196194ea27bd49adf3551e2aceb83498eb73fe","Linux >= c042c505210dc3453f378df432c10fff3d471bc5 < 190a8c48ff623c3d67cb295b4536a660db2012aa","Linux 6.16"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T15:07:55.880720Z"},"exploitAvailable":true,"published":"2026-04-02","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:09:55.614Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-23415","references":[{"url":"https://git.kernel.org/stable/c/853f70c67d1b37e368fdcb3e328c4b8c04f53ac0"},{"url":"https://git.kernel.org/stable/c/7e196194ea27bd49adf3551e2aceb83498eb73fe"},{"url":"https://git.kernel.org/stable/c/190a8c48ff623c3d67cb295b4536a660db2012aa"}],"tags":["cve.org","exploit-available"],"epss":0.00131,"epssPercentile":0.02418,"exploits":{"github":1,"githubRepos":["https://github.com/addman2/uaf-exploit-cve-2026-23415"],"checkedAt":"2026-10-16T17:25:21.009Z"},"ingestedAt":"2026-10-16T17:24:46.645Z","slug":"CVE-2026-23415","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nfutex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()\n\nDuring futex_key_to_node_opt() execution, vma->vm_policy is read under\nspeculative mmap lock and RCU. Concurrently, mbind() may call\nvma_replace_policy() which frees the old mempolicy immediately via\nkmem_cache_free().\n\nThis creates a race where __futex_key_to_node() dereferences a freed\nmempolicy pointer, causing a use-after-free read of mpol->mode.\n\n[  151.412631] BUG: KASAN: slab-use-after-free in __futex_key_to_node (kernel/futex/core.c:349)\n[  151.414046] Read of size 2 at addr ffff888001c49634 by task e/87\n\n[  151.415969] Call Trace:\n\n[  151.416732]  __asan_load2 (mm/kasan/generic.c:271)\n[  151.416777]  __futex_key_to_node (kernel/futex/core.c:349)\n[  151.416822]  get_futex_key (kernel/futex/core.c:374 kernel/futex/core.c:386 kernel/futex/core.c:593)\n\nFix by adding rcu to __mpol_put().\n\n## Affected\n\n- `Linux >= c042c505210dc3453f378df432c10fff3d471bc5 < 853f70c67d1b37e368fdcb3e328c4b8c04f53ac0`\n- `Linux >= c042c505210dc3453f378df432c10fff3d471bc5 < 7e196194ea27bd49adf3551e2aceb83498eb73fe`\n- `Linux >= c042c505210dc3453f378df432c10fff3d471bc5 < 190a8c48ff623c3d67cb295b4536a660db2012aa`\n- `Linux 6.16`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":55,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":12,"ransomware":0},"changes":[]}