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Fencer Intel
high 8.8

CVE-2026-63801 json

tipc: fix slab-use-after-free Read in tipc_aead_decrypt_done

published 3mo ago modified 23d ago also EUVD-2026-45467

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 44%
public exploits
0
none known

Summary

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

tipc: fix slab-use-after-free Read in tipc_aead_decrypt_done

tipc_aead_decrypt() goes straight from tipc_bearer_hold(b) to crypto_aead_decrypt(req) without taking a reference on the netns, unlike the encrypt path. When crypto_aead_decrypt() is offloaded asynchronously (e.g. the SIMD aead wrapper queuing to cryptd), the cryptd worker runs tipc_aead_decrypt_done() later. If the bearer's netns is torn down in the meantime, cleanup_net() -> tipc_exit_net() -> tipc_crypto_stop() frees the per-netns tipc_crypto, and the completion then reads it: tipc_aead_decrypt_done() dereferences aead->crypto->stats and aead->crypto->net, and tipc_crypto_rcv_complete() dereferences aead->crypto->aead[] and the node table -- reading freed memory.

Decoded KASAN splat (v7.1-rc7, CONFIG_KASAN_INLINE + TIPC + TIPC_CRYPTO):

BUG: KASAN: slab-use-after-free in tipc_aead_decrypt_done (net/tipc/crypto.c:999) Read of size 8 at addr ffff8881056258a8 by task kworker/u16:2/51 Workqueue: events_unbound Call Trace: tipc_aead_decrypt_done (net/tipc/crypto.c:999) process_one_work (kernel/workqueue.c:3314) worker_thread (kernel/workqueue.c:3397 kernel/workqueue.c:3478) kthread (kernel/kthread.c:436) ret_from_fork (arch/x86/kernel/process.c:158) ret_from_fork_asm (arch/x86/entry/entry_64.S:245)

Allocated by task 169: __kasan_kmalloc (mm/kasan/common.c:398 mm/kasan/common.c:415) tipc_crypto_start (net/tipc/crypto.c:1502) tipc_init_net (net/tipc/core.c:72) ops_init (net/core/net_namespace.c:137) setup_net (net/core/net_namespace.c:446) copy_net_ns (net/core/net_namespace.c:579) create_new_namespaces (kernel/nsproxy.c:132) __x64_sys_unshare (kernel/fork.c:3316) do_syscall_64 (arch/x86/entry/syscall_64.c:63) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)

Freed by task 8: kfree (mm/slub.c:6566) tipc_exit_net (net/tipc/core.c:119) cleanup_net (net/core/net_namespace.c:704) process_one_work (kernel/workqueue.c:3314) kthread (kernel/kthread.c:436)

This is the same class of bug that commit e279024617134 ("net/tipc: fix slab-use-after-free Read in tipc_aead_encrypt_done") fixed for the encrypt side. The encrypt path takes maybe_get_net(aead->crypto->net) before crypto_aead_encrypt() and drops it with put_net() on the synchronous return paths and in tipc_aead_encrypt_done(); the -EINPROGRESS/-EBUSY return keeps the reference for the async callback to release. The decrypt path was left without the equivalent guard.

Mirror the encrypt-side fix on the decrypt path: take a net reference before crypto_aead_decrypt() (failing with -ENODEV and the matching bearer put if it cannot be acquired), keep it across the -EINPROGRESS/-EBUSY async return, and drop it with put_net() on the synchronous success/error return and at the end of tipc_aead_decrypt_done().

Reproduced under KASAN on v7.1-rc7: a UDP bearer with a cluster key is flooded with crafted encrypted frames from an unknown peer (driving the cluster-key decrypt path) while the bearer's netns is repeatedly torn down. The completion must run asynchronously to outlive tipc_crypto_stop(); on x86 the stock aesni gcm(aes) now decrypts synchronously, so the async path was exercised via cryptd offload. The unguarded aead->crypto dereference in tipc_aead_decrypt_done() is the unpatched upstream path; tipc_aead_decrypt() still lacks maybe_get_net(aead->crypto->net), so the completion can outlive the free on any config where crypto_aead_decrypt() goes async.

Found by 0sec automated security-research tooling (https://0sec.ai).

Patch / fix

  • Linux Linux 5.10.260, 5.15.211, 6.1.177, 6.6.144, 6.12.95, 6.18.38, 7.1.3, 7.2
  • linux Debian 12 6.1.177-1
  • linux Debian 13 6.12.95-1
  • linux Debian 14 7.1.3-1

debian advisories DEBIAN-CVE-2026-63801

  • 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 7.0.0-31.31
  • 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 7.0.0-1012.12
  • 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-2026-63801

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 6.12.0-211.67.1.el10_2
  • rv RHEL 10.2 6.12.0-211.67.1.el10_2
  • perf RHEL 10.2 6.12.0-211.67.1.el10_2
  • rtla RHEL 10.2 6.12.0-211.67.1.el10_2
  • libperf RHEL 10.2 6.12.0-211.67.1.el10_2
  • kernel-rt RHEL 10.2 6.12.0-211.67.1.el10_2
  • kernel-64k RHEL 10.2 6.12.0-211.67.1.el10_2
  • kernel-core RHEL 10.2 6.12.0-211.67.1.el10_2

red hat advisories RHSA-2026:85321RHSA-2026:67150RHSA-2026:66325RHSA-2026:66324

  • 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-2026:11339-1

  • kernel AlmaLinux 10 6.12.0-211.67.1.el10_2
  • rv AlmaLinux 10 6.12.0-211.67.1.el10_2
  • perf AlmaLinux 10 6.12.0-211.67.1.el10_2
  • rtla AlmaLinux 10 6.12.0-211.67.1.el10_2
  • libperf AlmaLinux 10 6.12.0-211.67.1.el10_2
  • kernel-rt AlmaLinux 10 6.12.0-211.67.1.el10_2
  • kernel-64k AlmaLinux 10 6.12.0-211.67.1.el10_2
  • kernel-core AlmaLinux 10 6.12.0-211.67.1.el10_2

almalinux advisories ALSA-2026:85321ALSA-2026:67150ALSA-2026:66324ALSA-2026:66325

  • kernel Rocky Linux 10 6.12.0-211.67.1.el10_2
  • kernel Rocky Linux 9 5.14.0-687.47.1.el9_8
  • kernel-rt Rocky Linux 8 4.18.0-553.162.1.rt7.503.el8_10
  • kernel Rocky Linux 8 4.18.0-553.162.1.el8_10

rocky linux advisories RLSA-2026:85321RLSA-2026:67150RLSA-2026:66324RLSA-2026:66325

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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-2026-63801 updated cvss 5.3

kernel: tipc: fix slab-use-after-free Read in tipc_aead_decrypt_done

  • 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 6.12.0-211.67.1.el10_2
    fixed: vendor fix RHSA-2026:85321
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.47.1.el9_8, perf 5.14.0-687.47.1.el9_8, rtla 5.14.0-687.47.1.el9_8, python3-perf 5.14.0-687.47.1.el9_8, kernel-devel-matched 5.14.0-687.47.1.el9_8, kernel-64k-devel-matched 5.14.0-687.47.1.el9_8, +7 more
    fixed: vendor fix RHSA-2026:67150
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.67.1.el10_2, perf 6.12.0-211.67.1.el10_2, rtla 6.12.0-211.67.1.el10_2, python3-perf 6.12.0-211.67.1.el10_2, kernel-devel-matched 6.12.0-211.67.1.el10_2, kernel-64k-devel-matched 6.12.0-211.67.1.el10_2, +7 more
    fixed: vendor fix RHSA-2026:85321
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.162.1.el8_10, kernel 4.18.0-553.162.1.el8_10, bpftool 4.18.0-553.162.1.el8_10, kernel-core 4.18.0-553.162.1.el8_10, kernel-tools 4.18.0-553.162.1.el8_10, python3-perf 4.18.0-553.162.1.el8_10, +15 more
    fixed: vendor fix RHSA-2026:66325
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.47.1.el9_8, kernel-64k 5.14.0-687.47.1.el9_8, kernel-core 5.14.0-687.47.1.el9_8, kernel-tools 5.14.0-687.47.1.el9_8, kernel-modules 5.14.0-687.47.1.el9_8, kernel-64k-core 5.14.0-687.47.1.el9_8, +27 more
    fixed: vendor fix RHSA-2026:67150
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.67.1.el10_2, kernel-64k 6.12.0-211.67.1.el10_2, kernel-core 6.12.0-211.67.1.el10_2, kernel-tools 6.12.0-211.67.1.el10_2, kernel-modules 6.12.0-211.67.1.el10_2, kernel-64k-core 6.12.0-211.67.1.el10_2, +28 more
    fixed: vendor fix RHSA-2026:85321
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.47.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.47.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.47.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.47.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.47.1.el9_8
    fixed: vendor fix RHSA-2026:67150
show 10 more
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.67.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.67.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.67.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.67.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.67.1.el10_2
    fixed: vendor fix RHSA-2026:85321
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.162.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.162.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.162.1.el8_10
    fixed: vendor fix RHSA-2026:66325
  • Red Hat Enterprise Linux Hidden (v. 10) kernel-modules-internal 6.12.0-211.67.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.67.1.el10_2
    fixed: vendor fix RHSA-2026:85321
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.162.1.rt7.503.el8_10, kernel-rt-kvm 4.18.0-553.162.1.rt7.503.el8_10, kernel-rt-core 4.18.0-553.162.1.rt7.503.el8_10, kernel-rt-modules 4.18.0-553.162.1.rt7.503.el8_10, kernel-rt-debug-kvm 4.18.0-553.162.1.rt7.503.el8_10, kernel-rt-debug-core 4.18.0-553.162.1.rt7.503.el8_10, +4 more
    fixed: vendor fix RHSA-2026:66324
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.47.1.el9_8, kernel-rt-64k 5.14.0-687.47.1.el9_8, kernel-rt-core 5.14.0-687.47.1.el9_8, kernel-rt-modules 5.14.0-687.47.1.el9_8, kernel-rt-64k-core 5.14.0-687.47.1.el9_8, kernel-rt-debug-core 5.14.0-687.47.1.el9_8, +14 more
    fixed: vendor fix RHSA-2026:67150
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.67.1.el10_2, kernel-rt-64k 6.12.0-211.67.1.el10_2, kernel-rt-core 6.12.0-211.67.1.el10_2, kernel-rt-modules 6.12.0-211.67.1.el10_2, kernel-rt-64k-core 6.12.0-211.67.1.el10_2, kernel-rt-debug-core 6.12.0-211.67.1.el10_2, +14 more
    fixed: vendor fix RHSA-2026:85321
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.47.1.el9_8, kernel-rt-core 5.14.0-687.47.1.el9_8, kernel-rt-modules 5.14.0-687.47.1.el9_8, kernel-rt-debug-core 5.14.0-687.47.1.el9_8, kernel-rt-modules-core 5.14.0-687.47.1.el9_8, kernel-rt-debug-modules 5.14.0-687.47.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:67150
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.67.1.el10_2, kernel-rt-core 6.12.0-211.67.1.el10_2, kernel-rt-modules 6.12.0-211.67.1.el10_2, kernel-rt-debug-core 6.12.0-211.67.1.el10_2, kernel-rt-modules-core 6.12.0-211.67.1.el10_2, kernel-rt-debug-modules 6.12.0-211.67.1.el10_2, +4 more
    fixed: vendor fix RHSA-2026:85321
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.162.1.rt7.503.el8_10, kernel-rt-core 4.18.0-553.162.1.rt7.503.el8_10, kernel-rt-modules 4.18.0-553.162.1.rt7.503.el8_10, kernel-rt-debug-core 4.18.0-553.162.1.rt7.503.el8_10, kernel-rt-debug-modules 4.18.0-553.162.1.rt7.503.el8_10, kernel-rt-modules-extra 4.18.0-553.162.1.rt7.503.el8_10, +2 more
    fixed: vendor fix RHSA-2026:66324
  • 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
total
Assessed
26d ago

Exploit prediction

0.51% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

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