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Fencer Intel
high 7.8

CVE-2026-46015 json

tcp: call sk_data_ready() after listener migration

published 5mo ago modified 21d ago also EUVD-2026-32396

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 3%
public exploits
0
none known

Summary

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

tcp: call sk_data_ready() after listener migration

When inet_csk_listen_stop() migrates an established child socket from a closing listener to another socket in the same SO_REUSEPORT group, the target listener gets a new accept-queue entry via inet_csk_reqsk_queue_add(), but that path never notifies the target listener's waiters. A nonblocking accept() still works because it checks the queue directly, but poll()/epoll_wait() waiters and blocking accept() callers can also remain asleep indefinitely.

Call READ_ONCE(nsk->sk_data_ready)(nsk) after a successful migration in inet_csk_listen_stop().

However, after inet_csk_reqsk_queue_add() succeeds, the ref acquired in reuseport_migrate_sock() is effectively transferred to nreq->rsk_listener. Another CPU can then dequeue nreq via accept() or listener shutdown, hit reqsk_put(), and drop that listener ref. Since listeners are SOCK_RCU_FREE, wrap the post-queue_add() dereferences of nsk in rcu_read_lock()/rcu_read_unlock(), which also covers the existing sock_net(nsk) access in that path.

The reqsk_timer_handler() path does not need the same changes for two reasons: half-open requests become readable only after the final ACK, where tcp_child_process() already wakes the listener; and once nreq is visible via inet_ehash_insert(), the success path no longer touches nsk directly.

Patch / fix

  • Linux Linux 5.15.209, 6.1.175, 6.6.140, 6.12.86, 6.18.27, 7.0.4, 7.1
  • linux Debian 12 6.1.176-1
  • linux Debian 13 6.12.86-1
  • linux Debian 14 7.0.4-1

debian advisories DEBIAN-CVE-2026-46015

  • linux Ubuntu 22.04 LTS 5.15.0-186.196
  • linux Ubuntu 24.04 LTS 6.8.0-136.136
  • linux Ubuntu 26.04 LTS 7.0.0-27.27
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1112.119
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1061.64
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1008.8
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1112.122
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1064.72

ubuntu advisories UBUNTU-CVE-2026-46015

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 9 5.14.0-687.46.1.el9_8
  • rv RHEL 9 5.14.0-687.46.1.el9_8
  • perf RHEL 9 5.14.0-687.46.1.el9_8
  • rtla RHEL 9 5.14.0-687.46.1.el9_8
  • libperf RHEL 9 5.14.0-687.46.1.el9_8
  • kernel-rt RHEL 9 5.14.0-687.46.1.el9_8
  • kernel-64k RHEL 9 5.14.0-687.46.1.el9_8
  • kernel-core RHEL 9 5.14.0-687.46.1.el9_8

red hat advisories RHSA-2026:66180RHSA-2026:64775

  • kernel-rt Real Time Module 15 SP7 6.4.0-150700.7.72.1
  • kernel-syms-rt Real Time Module 15 SP7 6.4.0-150700.7.72.1
  • kernel-source-rt Real Time Module 15 SP7 6.4.0-150700.7.72.1
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.78.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.78.1
  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.53.78.1
  • kernel-source SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 6.4.0-150700.53.78.1
  • kernel-default SLE Workstation Extension 15 SP7, SLE Module for Legacy 15 SP7, SLE Module for Basesystem 15 SP7 +2 more 6.4.0-150700.53.78.1

suse advisories SUSE-SU-2026:3810-1SUSE-SU-2026:3790-1SUSE-SU-2026:23244-1SUSE-SU-2026:23241-1SUSE-SU-2026:23194-1SUSE-SU-2026:23193-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.37.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.37.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.37.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.37.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.37.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.37.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.37.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.37.1

opensuse advisories openSUSE-SU-2026:21555-1openSUSE-SU-2026:10954-1

  • kernel AlmaLinux 9 5.14.0-687.46.1.el9_8
  • rv AlmaLinux 9 5.14.0-687.46.1.el9_8
  • perf AlmaLinux 9 5.14.0-687.46.1.el9_8
  • rtla AlmaLinux 9 5.14.0-687.46.1.el9_8
  • libperf AlmaLinux 9 5.14.0-687.46.1.el9_8
  • kernel-rt AlmaLinux 9 5.14.0-687.46.1.el9_8
  • kernel-64k AlmaLinux 9 5.14.0-687.46.1.el9_8
  • kernel-core AlmaLinux 9 5.14.0-687.46.1.el9_8

almalinux advisories ALSA-2026:66180

  • kernel Rocky Linux 9 5.14.0-687.46.1.el9_8
  • kernel Rocky Linux 10 6.12.0-211.52.1.el10_2

rocky linux advisories RLSA-2026:66180RLSA-2026:64775

  • kernel Azure Linux 3.0 6.6.141.1-1

azure linux advisories AZL-88551

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-2026-46015 updated cvss 7.0

kernel: tcp: call sk_data_ready() after listener migration

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: no fix planned “Out of support scope”
  • 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 5.14.0-687.46.1.el9_8, perf 5.14.0-687.46.1.el9_8, rtla 5.14.0-687.46.1.el9_8, python3-perf 5.14.0-687.46.1.el9_8, kernel-devel-matched 5.14.0-687.46.1.el9_8, kernel-64k-devel-matched 5.14.0-687.46.1.el9_8, +7 more
    fixed: vendor fix RHSA-2026:66180
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.52.1.el10_2, perf 6.12.0-211.52.1.el10_2, rtla 6.12.0-211.52.1.el10_2, python3-perf 6.12.0-211.52.1.el10_2, kernel-devel-matched 6.12.0-211.52.1.el10_2, kernel-64k-devel-matched 6.12.0-211.52.1.el10_2, +7 more
    fixed: vendor fix RHSA-2026:64775
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.46.1.el9_8, kernel-64k 5.14.0-687.46.1.el9_8, kernel-core 5.14.0-687.46.1.el9_8, kernel-tools 5.14.0-687.46.1.el9_8, kernel-modules 5.14.0-687.46.1.el9_8, kernel-64k-core 5.14.0-687.46.1.el9_8, +27 more
    fixed: vendor fix RHSA-2026:66180
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.52.1.el10_2, kernel-64k 6.12.0-211.52.1.el10_2, kernel-core 6.12.0-211.52.1.el10_2, kernel-tools 6.12.0-211.52.1.el10_2, kernel-modules 6.12.0-211.52.1.el10_2, kernel-64k-core 6.12.0-211.52.1.el10_2, +28 more
    fixed: vendor fix RHSA-2026:64775
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.46.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.46.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.46.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.46.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.46.1.el9_8
    fixed: vendor fix RHSA-2026:66180
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.52.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.52.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.52.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.52.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.52.1.el10_2
    fixed: vendor fix RHSA-2026:64775
show 5 more
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.46.1.el9_8, kernel-rt-64k 5.14.0-687.46.1.el9_8, kernel-rt-core 5.14.0-687.46.1.el9_8, kernel-rt-modules 5.14.0-687.46.1.el9_8, kernel-rt-64k-core 5.14.0-687.46.1.el9_8, kernel-rt-debug-core 5.14.0-687.46.1.el9_8, +14 more
    fixed: vendor fix RHSA-2026:66180
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.52.1.el10_2, kernel-rt-64k 6.12.0-211.52.1.el10_2, kernel-rt-core 6.12.0-211.52.1.el10_2, kernel-rt-modules 6.12.0-211.52.1.el10_2, kernel-rt-64k-core 6.12.0-211.52.1.el10_2, kernel-rt-debug-core 6.12.0-211.52.1.el10_2, +14 more
    fixed: vendor fix RHSA-2026:64775
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.46.1.el9_8, kernel-rt-core 5.14.0-687.46.1.el9_8, kernel-rt-modules 5.14.0-687.46.1.el9_8, kernel-rt-debug-core 5.14.0-687.46.1.el9_8, kernel-rt-modules-core 5.14.0-687.46.1.el9_8, kernel-rt-debug-modules 5.14.0-687.46.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:66180
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.52.1.el10_2, kernel-rt-core 6.12.0-211.52.1.el10_2, kernel-rt-modules 6.12.0-211.52.1.el10_2, kernel-rt-debug-core 6.12.0-211.52.1.el10_2, kernel-rt-modules-core 6.12.0-211.52.1.el10_2, kernel-rt-debug-modules 6.12.0-211.52.1.el10_2, +4 more
    fixed: vendor fix RHSA-2026:64775
  • 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
    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 ICSA-26-295-11 updated cvss 7.8

Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.7 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.7 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.7 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.7 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.7
    affected: mitigation, no fix available

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

cisa ICSA-26-295-16 updated cvss 7.8

Siemens SIMATIC S7-1500 TM MFP

  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
    affected: mitigation, no fix available

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
24d ago

Exploit prediction

0.14% chance of exploitation in the next 30 days, higher than 3% 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

Affected products

  • Linux Linux
  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

Classification

Weakness
  • CWE-408 Incorrect Behavior Order: Early Amplification
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.