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CVE-2026-23415 (GCVE-0-2026-23415)

Vulnerability from cvelistv5 – Published: 2026-04-02 11:40 – Updated: 2026-08-05 12:21
VLAI
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: 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().
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: c042c505210dc3453f378df432c10fff3d471bc5 , < 853f70c67d1b37e368fdcb3e328c4b8c04f53ac0 (git)
Affected: c042c505210dc3453f378df432c10fff3d471bc5 , < 7e196194ea27bd49adf3551e2aceb83498eb73fe (git)
Affected: c042c505210dc3453f378df432c10fff3d471bc5 , < 190a8c48ff623c3d67cb295b4536a660db2012aa (git)
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Linux Linux Affected: 6.16
Unaffected: 0 , < 6.16 (semver)
Unaffected: 6.18.21 , ≤ 6.18.* (semver)
Unaffected: 6.19.11 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
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      "current_release_date": "2026-08-11T15:27:24+00:00",
      "cve": "CVE-2026-23415",
      "id": "CVE-2026-23415",
      "initial_release_date": "2026-04-02T00:00:00+00:00",
      "product_status:fixed": "612",
      "product_status:known_affected": "22",
      "product_status:known_not_affected": "90",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-23415.json",
      "version": "3"
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}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.


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