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CVE-2026-64572 json

ipv4: fib: free fib_alias with kfree_rcu() on insert error path

published 3mo ago modified 5d ago also EUVD-2026-53266

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 10%
public exploits
0
none known

Summary

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

ipv4: fib: free fib_alias with kfree_rcu() on insert error path

fib_table_insert() publishes new_fa into the leaf's fa_list with fib_insert_alias() before calling the fib entry notifiers. When a notifier fails, the error path removes new_fa with fib_remove_alias() (hlist_del_rcu) and frees it right away with kmem_cache_free().

fib_table_lookup() walks that list under rcu_read_lock() only, so a concurrent lookup that already reached new_fa keeps reading it after the free:

BUG: KASAN: slab-use-after-free in fib_table_lookup (net/ipv4/fib_trie.c:1601) Read of size 1 at addr ffff88810676d4eb by task exploit/297 Call Trace: fib_table_lookup (net/ipv4/fib_trie.c:1601) ip_route_output_key_hash_rcu (net/ipv4/route.c:2814) ip_route_output_key_hash (net/ipv4/route.c:2705) __ip4_datagram_connect (net/ipv4/datagram.c:49) udp_connect (net/ipv4/udp.c:2144) __sys_connect (net/socket.c:2167) __x64_sys_connect (net/socket.c:2173) do_syscall_64 entry_SYSCALL_64_after_hwframe which belongs to the cache ip_fib_alias of size 56

Triggering the error path needs CAP_NET_ADMIN and a registered fib notifier that can reject a route; a netdevsim device whose IPv4 FIB resource is exhausted is enough.

Free new_fa with alias_free_mem_rcu(), as fib_table_delete() already does for a fib_alias removed from the trie.

Patch / fix

  • Linux Linux 5.10.265, 5.15.216, 6.1.183, 6.6.148, 6.12.101, 6.18.42, 7.1.6, 7.2
  • linux Debian 12 6.1.187-1
  • linux Debian 13 6.12.101-1
  • linux Debian 14 7.1.6-1
  • linux-6.12 Debian 12 6.12.101-1~deb12u1

debian advisories DEBIAN-CVE-2026-64572

  • linux Ubuntu 22.04 LTS 5.15.0-198.208
  • linux Ubuntu 24.04 LTS 6.8.0-147.147
  • linux Ubuntu 26.04 LTS 7.0.0-38.38
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1117.124
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1067.70
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1014.14
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1118.128
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1071.79

ubuntu advisories UBUNTU-CVE-2026-64572

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-64kb SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS, SLE High Performance Computing 15 SP5-ESPOS 5.14.21-150500.55.189.1
  • kernel-syms SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 5.14.21-150500.55.189.1
  • kernel-source SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 5.14.21-150500.55.189.1
  • kernel-default SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +3 more 5.14.21-150500.55.189.1
  • kernel-obs-build SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 5.14.21-150500.55.189.1
  • kernel-default-base SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 5.14.21-150500.55.189.1.150500.6.87.4
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.81.1

suse advisories SUSE-SU-2026:4595-1SUSE-SU-2026:4254-1SUSE-SU-2026:4369-1SUSE-SU-2026:4347-1SUSE-SU-2026:4284-1SUSE-SU-2026:23887-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.38.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.38.1

opensuse advisories openSUSE-SU-2026:21910-1openSUSE-SU-2026:11476-1

  • kernel AlmaLinux 10 6.12.0-211.68.1.el10_2
  • rv AlmaLinux 10 6.12.0-211.68.1.el10_2
  • perf AlmaLinux 10 6.12.0-211.68.1.el10_2
  • rtla AlmaLinux 10 6.12.0-211.68.1.el10_2
  • libperf AlmaLinux 10 6.12.0-211.68.1.el10_2
  • kernel-rt AlmaLinux 10 6.12.0-211.68.1.el10_2
  • kernel-64k AlmaLinux 10 6.12.0-211.68.1.el10_2
  • kernel-core AlmaLinux 10 6.12.0-211.68.1.el10_2

almalinux advisories ALSA-2026:88477ALSA-2026:87374ALSA-2026:87375ALSA-2026:86033

  • kernel Rocky Linux 10 6.12.0-211.68.1.el10_2
  • kernel-rt Rocky Linux 8 4.18.0-553.177.1.rt7.518.el8_10
  • kernel Rocky Linux 8 4.18.0-553.177.1.el8_10
  • kernel Rocky Linux 9 5.14.0-687.59.1.el9_8

rocky linux advisories RLSA-2026:88477RLSA-2026:87374RLSA-2026:87375RLSA-2026:86033

  • kernel Azure Linux 3.0 6.6.150.1-1

azure linux advisories AZL-94473

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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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-2026-64572 updated cvss 7.1

kernel: ipv4: fib: free fib_alias with kfree_rcu() on insert error path

  • 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: workaround, no fix available
  • Red Hat Enterprise Linux kernel-modules-internal 6.12.0-211.68.1.el10_2
    fixed: vendor fix RHSA-2026:88477
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.59.1.el9_8, perf 5.14.0-687.59.1.el9_8, rtla 5.14.0-687.59.1.el9_8, python3-perf 5.14.0-687.59.1.el9_8, kernel-devel-matched 5.14.0-687.59.1.el9_8, kernel-64k-devel-matched 5.14.0-687.59.1.el9_8, +7 more
    fixed: vendor fix RHSA-2026:86033
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.68.1.el10_2, perf 6.12.0-211.68.1.el10_2, rtla 6.12.0-211.68.1.el10_2, python3-perf 6.12.0-211.68.1.el10_2, kernel-devel-matched 6.12.0-211.68.1.el10_2, kernel-64k-devel-matched 6.12.0-211.68.1.el10_2, +7 more
    fixed: vendor fix RHSA-2026:88477
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.177.1.el8_10, kernel 4.18.0-553.177.1.el8_10, bpftool 4.18.0-553.177.1.el8_10, kernel-core 4.18.0-553.177.1.el8_10, kernel-tools 4.18.0-553.177.1.el8_10, python3-perf 4.18.0-553.177.1.el8_10, +15 more
    fixed: vendor fix RHSA-2026:87375
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.59.1.el9_8, kernel-64k 5.14.0-687.59.1.el9_8, kernel-core 5.14.0-687.59.1.el9_8, kernel-tools 5.14.0-687.59.1.el9_8, kernel-modules 5.14.0-687.59.1.el9_8, kernel-64k-core 5.14.0-687.59.1.el9_8, +27 more
    fixed: vendor fix RHSA-2026:86033
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.68.1.el10_2, kernel-64k 6.12.0-211.68.1.el10_2, kernel-core 6.12.0-211.68.1.el10_2, kernel-tools 6.12.0-211.68.1.el10_2, kernel-modules 6.12.0-211.68.1.el10_2, kernel-64k-core 6.12.0-211.68.1.el10_2, +28 more
    fixed: vendor fix RHSA-2026:88477
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.59.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.59.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.59.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.59.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.59.1.el9_8
    fixed: vendor fix RHSA-2026:86033
show 10 more
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.68.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.68.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.68.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.68.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.68.1.el10_2
    fixed: vendor fix RHSA-2026:88477
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.177.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.177.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.177.1.el8_10
    fixed: vendor fix RHSA-2026:87375
  • Red Hat Enterprise Linux Hidden (v. 10) kernel-modules-internal 6.12.0-211.68.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.68.1.el10_2
    fixed: vendor fix RHSA-2026:88477
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-kvm 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-core 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-modules 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-debug-kvm 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-debug-core 4.18.0-553.177.1.rt7.518.el8_10, +4 more
    fixed: vendor fix RHSA-2026:87374
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.59.1.el9_8, kernel-rt-64k 5.14.0-687.59.1.el9_8, kernel-rt-core 5.14.0-687.59.1.el9_8, kernel-rt-modules 5.14.0-687.59.1.el9_8, kernel-rt-64k-core 5.14.0-687.59.1.el9_8, kernel-rt-debug-core 5.14.0-687.59.1.el9_8, +14 more
    fixed: vendor fix RHSA-2026:86033
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.68.1.el10_2, kernel-rt-64k 6.12.0-211.68.1.el10_2, kernel-rt-core 6.12.0-211.68.1.el10_2, kernel-rt-modules 6.12.0-211.68.1.el10_2, kernel-rt-64k-core 6.12.0-211.68.1.el10_2, kernel-rt-debug-core 6.12.0-211.68.1.el10_2, +14 more
    fixed: vendor fix RHSA-2026:88477
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.59.1.el9_8, kernel-rt-core 5.14.0-687.59.1.el9_8, kernel-rt-modules 5.14.0-687.59.1.el9_8, kernel-rt-debug-core 5.14.0-687.59.1.el9_8, kernel-rt-modules-core 5.14.0-687.59.1.el9_8, kernel-rt-debug-modules 5.14.0-687.59.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:86033
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.68.1.el10_2, kernel-rt-core 6.12.0-211.68.1.el10_2, kernel-rt-modules 6.12.0-211.68.1.el10_2, kernel-rt-debug-core 6.12.0-211.68.1.el10_2, kernel-rt-modules-core 6.12.0-211.68.1.el10_2, kernel-rt-debug-modules 6.12.0-211.68.1.el10_2, +4 more
    fixed: vendor fix RHSA-2026:88477
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-core 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-modules 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-debug-core 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-debug-modules 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-modules-extra 4.18.0-553.177.1.rt7.518.el8_10, +2 more
    fixed: vendor fix RHSA-2026:87374
  • 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
    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
partial
Assessed
5d ago

Exploit prediction

0.20% chance of exploitation in the next 30 days, higher than 10% of all scored CVEs (FIRST EPSS, 2026-11-11).

Affected products

  • Linux Linux

Classification

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.