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Fencer Vulns
high 7.8

CVE-2026-46259 json

procfs: fix missing RCU protection when reading real_parent in do_task_stat()

published 2026-06-03 5 mo ago modified 2026-10-19 20 d ago also EUVD-2026-34121

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 1%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

procfs: fix missing RCU protection when reading real_parent in do_task_stat()

When reading /proc/[pid]/stat, do_task_stat() accesses task->real_parent without proper RCU protection, which leads to:

cpu 0 cpu 1 ----- ----- do_task_stat var = task->real_parent release_task call_rcu(delayed_put_task_struct) task_tgid_nr_ns(var) rcu_read_lock <--- Too late to protect task->real_parent! task_pid_ptr <--- UAF! rcu_read_unlock

This patch uses task_ppid_nr_ns() instead of task_tgid_nr_ns() to add proper RCU protection for accessing task->real_parent.

Patch / fix

  • Linux Linux 5.10.252, 5.15.202, 6.1.165, 6.6.128, 6.12.75, 6.18.14, 6.19.4, 7.0
  • linux Debian 12 6.1.170-1
  • linux Debian 13 6.12.85-1
  • linux Debian 14 6.18.14-1

debian advisories DEBIAN-CVE-2026-46259

  • linux Ubuntu 22.04 LTS 5.15.0-186.196
  • linux Ubuntu 24.04 LTS 6.8.0-134.134
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1112.119
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1060.63
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1112.122
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1063.69
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1108.114
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1058.64

ubuntu advisories UBUNTU-CVE-2026-46259

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel RHEL 10.2 6.12.0-211.31.1.el10_2
  • rv RHEL 10.2 6.12.0-211.31.1.el10_2
  • perf RHEL 10.2 6.12.0-211.31.1.el10_2
  • rtla RHEL 10.2 6.12.0-211.31.1.el10_2
  • libperf RHEL 10.2 6.12.0-211.31.1.el10_2
  • kernel-rt RHEL 10.2 6.12.0-211.31.1.el10_2
  • kernel-64k RHEL 10.2 6.12.0-211.31.1.el10_2
  • kernel-core RHEL 10.2 6.12.0-211.31.1.el10_2

red hat advisories RHSA-2026:36541RHSA-2026:36348RHSA-2026:36349RHSA-2026:36018

  • kernel-syms SLES 16.0, Linux Micro Extras 6.2, SLES for SAP applications 16.0 6.12.0-160000.36.1
  • kernel-obs-build Linux Micro Extras 6.2 6.12.0-160000.36.1
  • kernel-rt Linux Micro 6.2 6.12.0-160000.36.1
  • kernel-64kb SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.36.1
  • kernel-source SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.36.1
  • kernel-default SLES 16.0, SLE High Availability Extension 16.0, Linux Micro 6.2 +1 more 6.12.0-160000.36.1
  • kernel-default-base SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.36.1.160000.2.17
  • kernel-azure SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.36.1

suse advisories SUSE-SU-2026:22742-1SUSE-SU-2026:22769-1SUSE-SU-2026:22835-1SUSE-SU-2026:22812-1SUSE-SU-2026:2799-1SUSE-SU-2026:2722-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.36.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.36.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.36.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.36.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.36.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.36.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.36.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.36.1

opensuse advisories openSUSE-SU-2026:21388-1

  • kernel AlmaLinux 10 6.12.0-211.31.1.el10_2
  • rv AlmaLinux 10 6.12.0-211.31.1.el10_2
  • perf AlmaLinux 10 6.12.0-211.31.1.el10_2
  • rtla AlmaLinux 10 6.12.0-211.31.1.el10_2
  • libperf AlmaLinux 10 6.12.0-211.31.1.el10_2
  • kernel-rt AlmaLinux 10 6.12.0-211.31.1.el10_2
  • kernel-64k AlmaLinux 10 6.12.0-211.31.1.el10_2
  • kernel-core AlmaLinux 10 6.12.0-211.31.1.el10_2

almalinux advisories ALSA-2026:36541ALSA-2026:36348ALSA-2026:36349ALSA-2026:36018

  • kernel Rocky Linux 9 5.14.0-687.22.1.el9_8

rocky linux advisories RLSA-2026:36018

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-2026-46259 updated cvss 7.1

kernel: procfs: fix missing RCU protection when reading real_parent in do_task_stat()

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 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
    affected: no fix available
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.22.1.el9_8, perf 5.14.0-687.22.1.el9_8, rtla 5.14.0-687.22.1.el9_8, python3-perf 5.14.0-687.22.1.el9_8, kernel-devel-matched 5.14.0-687.22.1.el9_8, kernel-64k-devel-matched 5.14.0-687.22.1.el9_8, +7 more
    fixed: vendor fix RHSA-2026:36018
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.31.1.el10_2, perf 6.12.0-211.31.1.el10_2, rtla 6.12.0-211.31.1.el10_2, python3-perf 6.12.0-211.31.1.el10_2, kernel-devel-matched 6.12.0-211.31.1.el10_2, kernel-64k-devel-matched 6.12.0-211.31.1.el10_2, +7 more
    fixed: vendor fix RHSA-2026:36541
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) perf 5.14.0-284.202.1.el9_2, rtla 5.14.0-284.202.1.el9_2, kernel-devel-matched 5.14.0-284.202.1.el9_2, kernel-64k-devel-matched 5.14.0-284.202.1.el9_2, kernel-debug-devel-matched 5.14.0-284.202.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.202.1.el9_2, +5 more
    fixed: vendor fix RHSA-2026:94477
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) rv 5.14.0-427.158.1.el9_4, perf 5.14.0-427.158.1.el9_4, rtla 5.14.0-427.158.1.el9_4, kernel-devel-matched 5.14.0-427.158.1.el9_4, kernel-64k-devel-matched 5.14.0-427.158.1.el9_4, kernel-debug-devel-matched 5.14.0-427.158.1.el9_4, +6 more
    fixed: vendor fix RHSA-2026:91489
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.140.1.el8_10, kernel 4.18.0-553.140.1.el8_10, bpftool 4.18.0-553.140.1.el8_10, kernel-core 4.18.0-553.140.1.el8_10, kernel-tools 4.18.0-553.140.1.el8_10, python3-perf 4.18.0-553.140.1.el8_10, +15 more
    fixed: vendor fix RHSA-2026:36349
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.22.1.el9_8, kernel-64k 5.14.0-687.22.1.el9_8, kernel-core 5.14.0-687.22.1.el9_8, kernel-tools 5.14.0-687.22.1.el9_8, kernel-modules 5.14.0-687.22.1.el9_8, kernel-64k-core 5.14.0-687.22.1.el9_8, +27 more
    fixed: vendor fix RHSA-2026:36018
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.31.1.el10_2, kernel-64k 6.12.0-211.31.1.el10_2, kernel-core 6.12.0-211.31.1.el10_2, kernel-tools 6.12.0-211.31.1.el10_2, kernel-modules 6.12.0-211.31.1.el10_2, kernel-64k-core 6.12.0-211.31.1.el10_2, +28 more
    fixed: vendor fix RHSA-2026:36541
show 23 more
  • Red Hat Enterprise Linux BaseOS AUS (v.8.4) perf 4.18.0-305.216.1.el8_4, kernel 4.18.0-305.216.1.el8_4, bpftool 4.18.0-305.216.1.el8_4, kernel-core 4.18.0-305.216.1.el8_4, kernel-tools 4.18.0-305.216.1.el8_4, python3-perf 4.18.0-305.216.1.el8_4, +8 more
    fixed: vendor fix RHSA-2026:91585
  • Red Hat Enterprise Linux BaseOS AUS (v.8.6) perf 4.18.0-372.227.1.el8_6, kernel 4.18.0-372.227.1.el8_6, bpftool 4.18.0-372.227.1.el8_6, kernel-core 4.18.0-372.227.1.el8_6, kernel-tools 4.18.0-372.227.1.el8_6, python3-perf 4.18.0-372.227.1.el8_6, +8 more
    fixed: vendor fix RHSA-2026:94996
  • Red Hat Enterprise Linux BaseOS E4S (v.8.8) perf 4.18.0-477.177.1.el8_8, kernel 4.18.0-477.177.1.el8_8, bpftool 4.18.0-477.177.1.el8_8, kernel-core 4.18.0-477.177.1.el8_8, kernel-tools 4.18.0-477.177.1.el8_8, python3-perf 4.18.0-477.177.1.el8_8, +9 more
    fixed: vendor fix RHSA-2026:92997
  • Red Hat Enterprise Linux BaseOS E4S (v.9.2) bpftool 7.0.0-284.202.1.el9_2, kernel 5.14.0-284.202.1.el9_2, kernel-64k 5.14.0-284.202.1.el9_2, kernel-core 5.14.0-284.202.1.el9_2, kernel-tools 5.14.0-284.202.1.el9_2, python3-perf 5.14.0-284.202.1.el9_2, +28 more
    fixed: vendor fix RHSA-2026:94477
  • Red Hat Enterprise Linux BaseOS E4S (v.9.4) bpftool 7.3.0-427.158.1.el9_4, kernel 5.14.0-427.158.1.el9_4, kernel-64k 5.14.0-427.158.1.el9_4, kernel-core 5.14.0-427.158.1.el9_4, kernel-tools 5.14.0-427.158.1.el9_4, python3-perf 5.14.0-427.158.1.el9_4, +28 more
    fixed: vendor fix RHSA-2026:91489
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) perf 4.18.0-305.216.1.el8_4, kernel 4.18.0-305.216.1.el8_4, bpftool 4.18.0-305.216.1.el8_4, kernel-core 4.18.0-305.216.1.el8_4, kernel-tools 4.18.0-305.216.1.el8_4, python3-perf 4.18.0-305.216.1.el8_4, +8 more
    fixed: vendor fix RHSA-2026:91585
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) perf 4.18.0-372.227.1.el8_6, kernel 4.18.0-372.227.1.el8_6, bpftool 4.18.0-372.227.1.el8_6, kernel-core 4.18.0-372.227.1.el8_6, kernel-tools 4.18.0-372.227.1.el8_6, python3-perf 4.18.0-372.227.1.el8_6, +8 more
    fixed: vendor fix RHSA-2026:94996
  • Red Hat Enterprise Linux BaseOS TUS (v.8.8) perf 4.18.0-477.177.1.el8_8, kernel 4.18.0-477.177.1.el8_8, bpftool 4.18.0-477.177.1.el8_8, kernel-core 4.18.0-477.177.1.el8_8, kernel-tools 4.18.0-477.177.1.el8_8, python3-perf 4.18.0-477.177.1.el8_8, +8 more
    fixed: vendor fix RHSA-2026:92997
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.22.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.22.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.22.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.22.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.22.1.el9_8
    fixed: vendor fix RHSA-2026:36018
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.31.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.31.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.31.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.31.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.31.1.el10_2
    fixed: vendor fix RHSA-2026:36541
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.140.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.140.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.140.1.el8_10
    fixed: vendor fix RHSA-2026:36349
  • Red Hat Enterprise Linux for Real Time (v. 7 ELS) kernel-rt 3.10.0-1160.169.1.rt56.1321.el7, kernel-rt-trace 3.10.0-1160.169.1.rt56.1321.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.169.1.rt56.1321.el7
    fixed: vendor fix RHSA-2026:95721
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.140.1.rt7.481.el8_10, kernel-rt-kvm 4.18.0-553.140.1.rt7.481.el8_10, kernel-rt-core 4.18.0-553.140.1.rt7.481.el8_10, kernel-rt-modules 4.18.0-553.140.1.rt7.481.el8_10, kernel-rt-debug-kvm 4.18.0-553.140.1.rt7.481.el8_10, kernel-rt-debug-core 4.18.0-553.140.1.rt7.481.el8_10, +4 more
    fixed: vendor fix RHSA-2026:36348
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.22.1.el9_8, kernel-rt-64k 5.14.0-687.22.1.el9_8, kernel-rt-core 5.14.0-687.22.1.el9_8, kernel-rt-modules 5.14.0-687.22.1.el9_8, kernel-rt-64k-core 5.14.0-687.22.1.el9_8, kernel-rt-debug-core 5.14.0-687.22.1.el9_8, +14 more
    fixed: vendor fix RHSA-2026:36018
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.31.1.el10_2, kernel-rt-64k 6.12.0-211.31.1.el10_2, kernel-rt-core 6.12.0-211.31.1.el10_2, kernel-rt-modules 6.12.0-211.31.1.el10_2, kernel-rt-64k-core 6.12.0-211.31.1.el10_2, kernel-rt-debug-core 6.12.0-211.31.1.el10_2, +14 more
    fixed: vendor fix RHSA-2026:36541
  • Red Hat Enterprise Linux Real Time E4S (v.9.2) kernel-rt 5.14.0-284.202.1.rt14.487.el9_2, kernel-rt-core 5.14.0-284.202.1.rt14.487.el9_2, kernel-rt-modules 5.14.0-284.202.1.rt14.487.el9_2, kernel-rt-debug-core 5.14.0-284.202.1.rt14.487.el9_2, kernel-rt-modules-core 5.14.0-284.202.1.rt14.487.el9_2, kernel-rt-debug-modules 5.14.0-284.202.1.rt14.487.el9_2, +4 more
    fixed: vendor fix RHSA-2026:94558
  • Red Hat Enterprise Linux Real Time E4S (v.9.4) kernel-rt 5.14.0-427.158.1.el9_4, kernel-rt-core 5.14.0-427.158.1.el9_4, kernel-rt-modules 5.14.0-427.158.1.el9_4, kernel-rt-debug-core 5.14.0-427.158.1.el9_4, kernel-rt-modules-core 5.14.0-427.158.1.el9_4, kernel-rt-debug-modules 5.14.0-427.158.1.el9_4, +4 more
    fixed: vendor fix RHSA-2026:91489
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.22.1.el9_8, kernel-rt-core 5.14.0-687.22.1.el9_8, kernel-rt-modules 5.14.0-687.22.1.el9_8, kernel-rt-debug-core 5.14.0-687.22.1.el9_8, kernel-rt-modules-core 5.14.0-687.22.1.el9_8, kernel-rt-debug-modules 5.14.0-687.22.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:36018
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.31.1.el10_2, kernel-rt-core 6.12.0-211.31.1.el10_2, kernel-rt-modules 6.12.0-211.31.1.el10_2, kernel-rt-debug-core 6.12.0-211.31.1.el10_2, kernel-rt-modules-core 6.12.0-211.31.1.el10_2, kernel-rt-debug-modules 6.12.0-211.31.1.el10_2, +4 more
    fixed: vendor fix RHSA-2026:36541
  • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2) kernel-rt 5.14.0-284.202.1.rt14.487.el9_2, kernel-rt-kvm 5.14.0-284.202.1.rt14.487.el9_2, kernel-rt-core 5.14.0-284.202.1.rt14.487.el9_2, kernel-rt-modules 5.14.0-284.202.1.rt14.487.el9_2, kernel-rt-debug-kvm 5.14.0-284.202.1.rt14.487.el9_2, kernel-rt-debug-core 5.14.0-284.202.1.rt14.487.el9_2, +6 more
    fixed: vendor fix RHSA-2026:94558
  • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4) kernel-rt 5.14.0-427.158.1.el9_4, kernel-rt-kvm 5.14.0-427.158.1.el9_4, kernel-rt-core 5.14.0-427.158.1.el9_4, kernel-rt-modules 5.14.0-427.158.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.158.1.el9_4, kernel-rt-debug-core 5.14.0-427.158.1.el9_4, +6 more
    fixed: vendor fix RHSA-2026:91489
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.140.1.rt7.481.el8_10, kernel-rt-core 4.18.0-553.140.1.rt7.481.el8_10, kernel-rt-modules 4.18.0-553.140.1.rt7.481.el8_10, kernel-rt-debug-core 4.18.0-553.140.1.rt7.481.el8_10, kernel-rt-debug-modules 4.18.0-553.140.1.rt7.481.el8_10, kernel-rt-modules-extra 4.18.0-553.140.1.rt7.481.el8_10, +2 more
    fixed: vendor fix RHSA-2026:36348
  • Red Hat Enterprise Linux Server (v. 7 ELS) perf 3.10.0-1160.169.1.el7, kernel 3.10.0-1160.169.1.el7, bpftool 3.10.0-1160.169.1.el7, python-perf 3.10.0-1160.169.1.el7, kernel-kdump 3.10.0-1160.169.1.el7, kernel-tools 3.10.0-1160.169.1.el7, +7 more Red Hat Enterprise Linux Server Optional (v. 7 ELS) kernel-debuginfo-common-ppc64 3.10.0-1160.169.1.el7, kernel-debuginfo-common-x86_64 3.10.0-1160.169.1.el7, kernel-debuginfo-common-ppc64le 3.10.0-1160.169.1.el7
    fixed: vendor fix RHSA-2026:95556

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
23 d ago

Exploit prediction

0.12% chance of exploitation in the next 30 days, higher than 1% of all scored CVEs (FIRST EPSS, 2026-11-08).

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

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns 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.