CVE-2026-23415
Vulnerability Summary
Timeline
Description
In the Linux kernel, the following vulnerability has been resolved: futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy() During futex_key_to_node_opt() execution, vma->vm_policy is read under speculative mmap lock and RCU. Concurrently, mbind() may call vma_replace_policy() which frees the old mempolicy immediately via kmem_cache_free(). This creates a race where __futex_key_to_node() dereferences a freed mempolicy pointer, causing a use-after-free read of mpol->mode. [ 151.412631] BUG: KASAN: slab-use-after-free in __futex_key_to_node (kernel/futex/core.c:349) [ 151.414046] Read of size 2 at addr ffff888001c49634 by task e/87 [ 151.415969] Call Trace: [ 151.416732] __asan_load2 (mm/kasan/generic.c:271) [ 151.416777] __futex_key_to_node (kernel/futex/core.c:349) [ 151.416822] get_futex_key (kernel/futex/core.c:374 kernel/futex/core.c:386 kernel/futex/core.c:593) Fix by adding rcu to __mpol_put().
CVSS Metrics
- v4.0•HIGH•Score: 7.3CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Trends
Current EPSS score: 0.13%• Percentile: 3%
Techniques & Countermeasures
- CWE-416•Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
Affected Systems
- debian•linux
< 6.19.11-1
- ubuntu•linux
all
- ubuntu•linux-allwinner-5.19
all
- ubuntu•linux-aws
all
- ubuntu•linux-aws-5.0
all
- ubuntu•linux-aws-5.11
all
- ubuntu•linux-aws-5.13
all
- ubuntu•linux-aws-5.19
all
- ubuntu•linux-aws-5.3
all
- ubuntu•linux-aws-5.8
all
- ubuntu•linux-aws-6.14
all
- ubuntu•linux-aws-6.17
all
- ubuntu•linux-aws-6.2
all
- ubuntu•linux-aws-6.5
all
- ubuntu•linux-azure
all | all
- ubuntu•linux-azure-5.11
all
- ubuntu•linux-azure-5.13
all
- ubuntu•linux-azure-5.19
all
- ubuntu•linux-azure-5.3
all
- ubuntu•linux-azure-5.8
all
- ubuntu•linux-azure-6.11
all
- ubuntu•linux-azure-6.17
all
- ubuntu•linux-azure-6.2
all
- ubuntu•linux-azure-6.5
all
- ubuntu•linux-azure-edge
all
- ubuntu•linux-azure-fde
all | all
- ubuntu•linux-azure-fde-5.19
all
- ubuntu•linux-azure-fde-6.2
all
- ubuntu•linux-bluefield
all
- ubuntu•linux-gcp
all | all
- ubuntu•linux-gcp-5.11
all
- ubuntu•linux-gcp-5.13
all
- ubuntu•linux-gcp-5.19
all
- ubuntu•linux-gcp-5.3
all
- ubuntu•linux-gcp-5.8
all
- ubuntu•linux-gcp-6.11
all
- ubuntu•linux-gcp-6.14
all
- ubuntu•linux-gcp-6.17
all
- ubuntu•linux-gcp-6.2
all
- ubuntu•linux-gcp-6.5
all
- ubuntu•linux-gke
all
- ubuntu•linux-gke-4.15
all
- ubuntu•linux-gke-5.15
all
- ubuntu•linux-gke-5.4
all
- ubuntu•linux-gkeop
all
- ubuntu•linux-gkeop-5.15
all
- ubuntu•linux-gkeop-5.4
all
- ubuntu•linux-hwe
all
- ubuntu•linux-hwe-5.11
all
- ubuntu•linux-hwe-5.13
all
Showing first 50 affected entries in server-rendered view.
References (7)
- https://git.kernel.org/stable/c/853f70c67d1b37e368fdcb3e328c4b8c04f53ac0
- https://git.kernel.org/stable/c/7e196194ea27bd49adf3551e2aceb83498eb73fe
- https://git.kernel.org/stable/c/190a8c48ff623c3d67cb295b4536a660db2012aa
- https://ubuntu.com/security/CVE-2026-23415
- https://www.cve.org/CVERecord?id=CVE-2026-23415
- https://git.kernel.org/linus/190a8c48ff623c3d67cb295b4536a660db2012aa
- https://security-tracker.debian.org/tracker/CVE-2026-23415