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high 7.8

CVE-2026-23415 json

futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()

published 7mo ago modified 21d ago also EUVD-2026-18196

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 6%
public exploits
0
none known

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().

Patch / fix

  • Linux Linux 6.18.21, 6.19.11, 7.0
  • linux Debian 14 6.19.11-1

debian advisories DEBIAN-CVE-2026-23415

  • kernel RHEL 10.2 6.12.0-211.46.1.el10_2
  • rv RHEL 10.2 6.12.0-211.46.1.el10_2
  • perf RHEL 10.2 6.12.0-211.46.1.el10_2
  • rtla RHEL 10.2 6.12.0-211.46.1.el10_2
  • libperf RHEL 10.2 6.12.0-211.46.1.el10_2
  • kernel-rt RHEL 10.2 6.12.0-211.46.1.el10_2
  • kernel-64k RHEL 10.2 6.12.0-211.46.1.el10_2
  • kernel-core RHEL 10.2 6.12.0-211.46.1.el10_2

red hat advisories RHSA-2026:53330RHSA-2026:51035

  • kernel AlmaLinux 10 6.12.0-211.46.1.el10_2
  • rv AlmaLinux 10 6.12.0-211.46.1.el10_2
  • perf AlmaLinux 10 6.12.0-211.46.1.el10_2
  • rtla AlmaLinux 10 6.12.0-211.46.1.el10_2
  • libperf AlmaLinux 10 6.12.0-211.46.1.el10_2
  • kernel-rt AlmaLinux 10 6.12.0-211.46.1.el10_2
  • kernel-64k AlmaLinux 10 6.12.0-211.46.1.el10_2
  • kernel-core AlmaLinux 10 6.12.0-211.46.1.el10_2

almalinux advisories ALSA-2026:53330ALSA-2026:51035

  • kernel Rocky Linux 10 6.12.0-211.46.1.el10_2
  • kernel Rocky Linux 9 5.14.0-687.36.1.el9_8
  • kernel Rocky Linux 9 5.14.0-687.36.1.el9_8.cloud.1.0

rocky linux advisories RLSA-2026:53330RLSA-2026:51035RXSA-2026:51035

Is CVE-2026-23415 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-23415 updated cvss 5.7

kernel: futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()

  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.36.1.el9_8, perf 5.14.0-687.36.1.el9_8, rtla 5.14.0-687.36.1.el9_8, python3-perf 5.14.0-687.36.1.el9_8, kernel-devel-matched 5.14.0-687.36.1.el9_8, kernel-64k-devel-matched 5.14.0-687.36.1.el9_8, +7 more
    fixed: vendor fix RHSA-2026:51035
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.46.1.el10_2, perf 6.12.0-211.46.1.el10_2, rtla 6.12.0-211.46.1.el10_2, python3-perf 6.12.0-211.46.1.el10_2, kernel-devel-matched 6.12.0-211.46.1.el10_2, kernel-64k-devel-matched 6.12.0-211.46.1.el10_2, +7 more
    fixed: vendor fix RHSA-2026:53330
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.36.1.el9_8, kernel-64k 5.14.0-687.36.1.el9_8, kernel-core 5.14.0-687.36.1.el9_8, kernel-tools 5.14.0-687.36.1.el9_8, kernel-modules 5.14.0-687.36.1.el9_8, kernel-64k-core 5.14.0-687.36.1.el9_8, +27 more
    fixed: vendor fix RHSA-2026:51035
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.46.1.el10_2, kernel-64k 6.12.0-211.46.1.el10_2, kernel-core 6.12.0-211.46.1.el10_2, kernel-tools 6.12.0-211.46.1.el10_2, kernel-modules 6.12.0-211.46.1.el10_2, kernel-64k-core 6.12.0-211.46.1.el10_2, +28 more
    fixed: vendor fix RHSA-2026:53330
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.36.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.36.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.36.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.36.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.36.1.el9_8
    fixed: vendor fix RHSA-2026:51035
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.46.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.46.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.46.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.46.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.46.1.el10_2
    fixed: vendor fix RHSA-2026:53330
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.36.1.el9_8, kernel-rt-64k 5.14.0-687.36.1.el9_8, kernel-rt-core 5.14.0-687.36.1.el9_8, kernel-rt-modules 5.14.0-687.36.1.el9_8, kernel-rt-64k-core 5.14.0-687.36.1.el9_8, kernel-rt-debug-core 5.14.0-687.36.1.el9_8, +14 more
    fixed: vendor fix RHSA-2026:51035
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.46.1.el10_2, kernel-rt-64k 6.12.0-211.46.1.el10_2, kernel-rt-core 6.12.0-211.46.1.el10_2, kernel-rt-modules 6.12.0-211.46.1.el10_2, kernel-rt-64k-core 6.12.0-211.46.1.el10_2, kernel-rt-debug-core 6.12.0-211.46.1.el10_2, +14 more
    fixed: vendor fix RHSA-2026:53330
show 3 more
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.36.1.el9_8, kernel-rt-core 5.14.0-687.36.1.el9_8, kernel-rt-modules 5.14.0-687.36.1.el9_8, kernel-rt-debug-core 5.14.0-687.36.1.el9_8, kernel-rt-modules-core 5.14.0-687.36.1.el9_8, kernel-rt-debug-modules 5.14.0-687.36.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:51035
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.46.1.el10_2, kernel-rt-core 6.12.0-211.46.1.el10_2, kernel-rt-modules 6.12.0-211.46.1.el10_2, kernel-rt-debug-core 6.12.0-211.46.1.el10_2, kernel-rt-modules-core 6.12.0-211.46.1.el10_2, kernel-rt-debug-modules 6.12.0-211.46.1.el10_2, +4 more
    fixed: vendor fix RHSA-2026:53330
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
24d ago

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.