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Fencer Vulns
high 8.8

CVE-2026-64115 json

vsock/vmci: fix UAF when peer resets connection during handshake

published 2026-07-19 3 mo ago modified 2026-10-19 20 d ago also EUVD-2026-45800

cvss
8.8
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 3%
public exploits
0
none known

Summary

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

vsock/vmci: fix UAF when peer resets connection during handshake

vmci_transport_recv_connecting_server() returned err = 0 for a peer RST in its default switch arm:

err = pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST ? 0 : -EINVAL;

That made vmci_transport_recv_listen() skip vsock_remove_pending(), leaving the pending socket on the listener's pending_links with sk_state = TCP_CLOSE while destroy: still dropped the explicit reference taken before schedule_delayed_work().

One second later vsock_pending_work() observed is_pending=true and performed full cleanup: vsock_remove_pending() then the two trailing sock_put(sk) calls -- the first reached refcount 0 and __sk_freed the socket, and the second wrote into the freed object:

BUG: KASAN: slab-use-after-free in refcount_warn_saturate Write of size 4 at addr ffff88800b1cac80 by task kworker Workqueue: events vsock_pending_work

Treat peer RST like any other unexpected packet type (err = -EINVAL). All destroy: arms now return err < 0, so vmci_transport_recv_listen() removes pending from pending_links synchronously and vsock_pending_work() takes the is_pending=false / !rejected branch, dropping only its own work reference. This also closes the multi-packet race Sashiko reported on v2: pending is removed from the list before any subsequent packet can find it.

The pre-existing sk_acceptq_removed() gap on the err < 0 path of vmci_transport_recv_listen() that Sashiko also noted is not introduced or changed by this patch.

Tested on lts-6.12.79 with KASAN: 52/100 unpatched -> 0/100 patched.

Patch / fix

  • Linux Linux 5.10.258, 5.15.209, 6.1.175, 6.6.142, 6.12.92, 6.18.34, 7.0.11, 7.1
  • linux Debian 12 6.1.176-1
  • linux Debian 13 6.12.94-1
  • linux Debian 14 7.0.12-1

debian advisories DEBIAN-CVE-2026-64115

  • linux Ubuntu 22.04 LTS 5.15.0-186.196
  • linux Ubuntu 24.04 LTS 6.8.0-139.139
  • linux Ubuntu 26.04 LTS 7.0.0-28.28
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1112.119
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1064.67
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1009.9
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1112.122
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1067.75

ubuntu advisories UBUNTU-CVE-2026-64115

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 6.12.0-211.64.1.el10_2
  • rv RHEL 10.2 6.12.0-211.64.1.el10_2
  • perf RHEL 10.2 6.12.0-211.64.1.el10_2
  • rtla RHEL 10.2 6.12.0-211.64.1.el10_2
  • libperf RHEL 10.2 6.12.0-211.64.1.el10_2
  • kernel-rt RHEL 10.2 6.12.0-211.64.1.el10_2
  • kernel-64k RHEL 10.2 6.12.0-211.64.1.el10_2
  • kernel-core RHEL 10.2 6.12.0-211.64.1.el10_2

red hat advisories RHSA-2026:77690RHSA-2026:77689RHSA-2026:77500RHSA-2026:77498

  • 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-2026:21910-1

  • kernel AlmaLinux 8 4.18.0-553.172.1.el8_10
  • perf AlmaLinux 8 4.18.0-553.172.1.el8_10
  • bpftool AlmaLinux 8 4.18.0-553.172.1.el8_10
  • kernel-core AlmaLinux 8 4.18.0-553.172.1.el8_10
  • kernel-tools AlmaLinux 8 4.18.0-553.172.1.el8_10
  • python3-perf AlmaLinux 8 4.18.0-553.172.1.el8_10
  • kernel-modules AlmaLinux 8 4.18.0-553.172.1.el8_10
  • kernel-zfcpdump AlmaLinux 8 4.18.0-553.172.1.el8_10

almalinux advisories ALSA-2026:77498ALSA-2026:77500ALSA-2026:77689ALSA-2026:77690

  • kernel Rocky Linux 10 6.12.0-211.64.1.el10_2
  • kernel Rocky Linux 9 5.14.0-687.56.1.el9_8
  • kernel-rt Rocky Linux 8 4.18.0-553.172.1.rt7.513.el8_10
  • kernel Rocky Linux 8 4.18.0-553.172.1.el8_10

rocky linux advisories RLSA-2026:77690RLSA-2026:77689RLSA-2026:77500RLSA-2026:77498

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-2026-64115 updated cvss 7.0

kernel: vsock/vmci: fix UAF when peer resets connection during handshake

  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 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 kernel-modules-internal 6.12.0-211.64.1.el10_2
    fixed: vendor fix RHSA-2026:77690
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.56.1.el9_8, perf 5.14.0-687.56.1.el9_8, rtla 5.14.0-687.56.1.el9_8, python3-perf 5.14.0-687.56.1.el9_8, kernel-devel-matched 5.14.0-687.56.1.el9_8, kernel-64k-devel-matched 5.14.0-687.56.1.el9_8, +7 more
    fixed: vendor fix RHSA-2026:77689
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.64.1.el10_2, perf 6.12.0-211.64.1.el10_2, rtla 6.12.0-211.64.1.el10_2, python3-perf 6.12.0-211.64.1.el10_2, kernel-devel-matched 6.12.0-211.64.1.el10_2, kernel-64k-devel-matched 6.12.0-211.64.1.el10_2, +7 more
    fixed: vendor fix RHSA-2026:77690
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.172.1.el8_10, kernel 4.18.0-553.172.1.el8_10, bpftool 4.18.0-553.172.1.el8_10, kernel-core 4.18.0-553.172.1.el8_10, kernel-tools 4.18.0-553.172.1.el8_10, python3-perf 4.18.0-553.172.1.el8_10, +15 more
    fixed: vendor fix RHSA-2026:77498
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.56.1.el9_8, kernel-64k 5.14.0-687.56.1.el9_8, kernel-core 5.14.0-687.56.1.el9_8, kernel-tools 5.14.0-687.56.1.el9_8, kernel-modules 5.14.0-687.56.1.el9_8, kernel-64k-core 5.14.0-687.56.1.el9_8, +27 more
    fixed: vendor fix RHSA-2026:77689
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.64.1.el10_2, kernel-64k 6.12.0-211.64.1.el10_2, kernel-core 6.12.0-211.64.1.el10_2, kernel-tools 6.12.0-211.64.1.el10_2, kernel-modules 6.12.0-211.64.1.el10_2, kernel-64k-core 6.12.0-211.64.1.el10_2, +28 more
    fixed: vendor fix RHSA-2026:77690
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.56.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.56.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.56.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.56.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.56.1.el9_8
    fixed: vendor fix RHSA-2026:77689
show 10 more
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.64.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.64.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.64.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.64.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.64.1.el10_2
    fixed: vendor fix RHSA-2026:77690
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.172.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.172.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.172.1.el8_10
    fixed: vendor fix RHSA-2026:77498
  • Red Hat Enterprise Linux Hidden (v. 10) kernel-modules-internal 6.12.0-211.64.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.64.1.el10_2
    fixed: vendor fix RHSA-2026:77690
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.172.1.rt7.513.el8_10, kernel-rt-kvm 4.18.0-553.172.1.rt7.513.el8_10, kernel-rt-core 4.18.0-553.172.1.rt7.513.el8_10, kernel-rt-modules 4.18.0-553.172.1.rt7.513.el8_10, kernel-rt-debug-kvm 4.18.0-553.172.1.rt7.513.el8_10, kernel-rt-debug-core 4.18.0-553.172.1.rt7.513.el8_10, +4 more
    fixed: vendor fix RHSA-2026:77500
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.56.1.el9_8, kernel-rt-64k 5.14.0-687.56.1.el9_8, kernel-rt-core 5.14.0-687.56.1.el9_8, kernel-rt-modules 5.14.0-687.56.1.el9_8, kernel-rt-64k-core 5.14.0-687.56.1.el9_8, kernel-rt-debug-core 5.14.0-687.56.1.el9_8, +14 more
    fixed: vendor fix RHSA-2026:77689
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.64.1.el10_2, kernel-rt-64k 6.12.0-211.64.1.el10_2, kernel-rt-core 6.12.0-211.64.1.el10_2, kernel-rt-modules 6.12.0-211.64.1.el10_2, kernel-rt-64k-core 6.12.0-211.64.1.el10_2, kernel-rt-debug-core 6.12.0-211.64.1.el10_2, +14 more
    fixed: vendor fix RHSA-2026:77690
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.56.1.el9_8, kernel-rt-core 5.14.0-687.56.1.el9_8, kernel-rt-modules 5.14.0-687.56.1.el9_8, kernel-rt-debug-core 5.14.0-687.56.1.el9_8, kernel-rt-modules-core 5.14.0-687.56.1.el9_8, kernel-rt-debug-modules 5.14.0-687.56.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:77689
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.64.1.el10_2, kernel-rt-core 6.12.0-211.64.1.el10_2, kernel-rt-modules 6.12.0-211.64.1.el10_2, kernel-rt-debug-core 6.12.0-211.64.1.el10_2, kernel-rt-modules-core 6.12.0-211.64.1.el10_2, kernel-rt-debug-modules 6.12.0-211.64.1.el10_2, +4 more
    fixed: vendor fix RHSA-2026:77690
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.172.1.rt7.513.el8_10, kernel-rt-core 4.18.0-553.172.1.rt7.513.el8_10, kernel-rt-modules 4.18.0-553.172.1.rt7.513.el8_10, kernel-rt-debug-core 4.18.0-553.172.1.rt7.513.el8_10, kernel-rt-debug-modules 4.18.0-553.172.1.rt7.513.el8_10, kernel-rt-modules-extra 4.18.0-553.172.1.rt7.513.el8_10, +2 more
    fixed: vendor fix RHSA-2026:77500
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 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
23 d ago

Exploit prediction

0.14% chance of exploitation in the next 30 days, higher than 3% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/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.