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Fencer Vulns
high 7.5

CVE-2024-26826 json

mptcp: fix data re-injection from stale subflow

published 2024-04-17 2 y ago modified 2026-08-05 3 mo ago also EUVD-2024-24088

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 51%
public exploits
0
none known

Summary

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

mptcp: fix data re-injection from stale subflow

When the MPTCP PM detects that a subflow is stale, all the packet scheduler must re-inject all the mptcp-level unacked data. To avoid acquiring unneeded locks, it first try to check if any unacked data is present at all in the RTX queue, but such check is currently broken, as it uses TCP-specific helper on an MPTCP socket.

Funnily enough fuzzers and static checkers are happy, as the accessed memory still belongs to the mptcp_sock struct, and even from a functional perspective the recovery completed successfully, as the short-cut test always failed.

A recent unrelated TCP change - commit d5fed5addb2b ("tcp: reorganize tcp_sock fast path variables") - exposed the issue, as the tcp field reorganization makes the mptcp code always skip the re-inection.

Fix the issue dropping the bogus call: we are on a slow path, the early optimization proved once again to be evil.

Patch / fix

  • Linux Linux 5.15.149, 6.1.79, 6.6.18, 6.7.6, 6.8
  • linux Debian 12 6.1.82-1
  • linux Debian 14, Debian 13 6.7.7-1

debian advisories DEBIAN-CVE-2024-26826

  • linux Ubuntu 22.04 LTS 5.15.0-106.116
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1061.67
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1059.67
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1058.63
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1054.57
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1058.63
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1063.72
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1044.51

ubuntu advisories UBUNTU-CVE-2024-26826

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 5.14.0-427.42.1.el9_4
  • rv RHEL 9 5.14.0-427.42.1.el9_4
  • perf RHEL 9 5.14.0-427.42.1.el9_4
  • rtla RHEL 9 5.14.0-427.42.1.el9_4
  • bpftool RHEL 9 7.3.0-427.42.1.el9_4
  • libperf RHEL 9 5.14.0-427.42.1.el9_4
  • kernel-rt RHEL 9 5.14.0-427.42.1.el9_4
  • kernel-64k RHEL 9 5.14.0-427.42.1.el9_4

red hat advisories RHSA-2024:8617RHSA-2024:8614RHSA-2024:8613RHSA-2024:6993RHSA-2024:4211RHSA-2024:5065

  • kernel-rt Linux Micro 6.0 6.4.0-9.1
  • kernel-source-rt Linux Micro 6.0 6.4.0-9.1
  • kernel-source Linux Micro 6.0 6.4.0-18.1
  • kernel-default Linux Micro 6.0 6.4.0-18.1
  • kernel-kvmsmall Linux Micro 6.0 6.4.0-18.1
  • kernel-default-base Linux Micro 6.0 6.4.0-17.1.1.51
  • kernel-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.5.1
  • kernel-syms-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.5.1

suse advisories SUSE-SU-2025:20028-1SUSE-SU-2025:20008-1SUSE-SU-2024:2973-1SUSE-SU-2024:2896-1SUSE-SU-2024:2802-1

  • kernel AlmaLinux 9 5.14.0-427.42.1.el9_4
  • rv AlmaLinux 9 5.14.0-427.42.1.el9_4
  • perf AlmaLinux 9 5.14.0-427.42.1.el9_4
  • rtla AlmaLinux 9 5.14.0-427.42.1.el9_4
  • bpftool AlmaLinux 9 7.3.0-427.42.1.el9_4
  • libperf AlmaLinux 9 5.14.0-427.42.1.el9_4
  • kernel-rt AlmaLinux 9 5.14.0-427.42.1.el9_4
  • kernel-64k AlmaLinux 9 5.14.0-427.42.1.el9_4

almalinux advisories ALSA-2024:8617ALSA-2024:4352ALSA-2024:4211

  • kernel Rocky Linux 9 5.14.0-427.42.1.el9_4
  • kernel-rt Rocky Linux 8 4.18.0-553.8.1.rt7.349.el8_10
  • kernel Rocky Linux 8 4.18.0-553.8.1.el8_10

rocky linux advisories RLSA-2024:8617RLSA-2024:4352RLSA-2024:4211

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-2024-26826 updated cvss 5.5

kernel: mptcp: fix data re-injection from stale subflow

  • 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 CodeReady Linux Builder EUS (v.8.8) kernel-debuginfo-common-x86_64 4.18.0-477.74.1.el8_8, kernel-debuginfo-common-aarch64 4.18.0-477.74.1.el8_8, kernel-debuginfo-common-ppc64le 4.18.0-477.74.1.el8_8
    fixed: vendor fix RHSA-2024:6993
  • Red Hat CodeReady Linux Builder EUS (v.9.2) kernel-debuginfo-common-s390x 5.14.0-284.90.1.el9_2, kernel-debuginfo-common-x86_64 5.14.0-284.90.1.el9_2, kernel-debuginfo-common-aarch64 5.14.0-284.90.1.el9_2, kernel-debuginfo-common-ppc64le 5.14.0-284.90.1.el9_2
    fixed: vendor fix RHSA-2024:8613
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-427.42.1.el9_4, perf 5.14.0-427.42.1.el9_4, rtla 5.14.0-427.42.1.el9_4, kernel-devel-matched 5.14.0-427.42.1.el9_4, kernel-64k-devel-matched 5.14.0-427.42.1.el9_4, kernel-debug-devel-matched 5.14.0-427.42.1.el9_4, +6 more
    fixed: vendor fix RHSA-2024:8617
  • Red Hat Enterprise Linux AppStream EUS (v.9.2) perf 5.14.0-284.90.1.el9_2, rtla 5.14.0-284.90.1.el9_2, kernel-devel-matched 5.14.0-284.90.1.el9_2, kernel-64k-devel-matched 5.14.0-284.90.1.el9_2, kernel-debug-devel-matched 5.14.0-284.90.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.90.1.el9_2, +5 more
    fixed: vendor fix RHSA-2024:8613
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.8.1.el8_10, kernel 4.18.0-553.8.1.el8_10, bpftool 4.18.0-553.8.1.el8_10, kernel-core 4.18.0-553.8.1.el8_10, kernel-tools 4.18.0-553.8.1.el8_10, python3-perf 4.18.0-553.8.1.el8_10, +15 more
    fixed: vendor fix RHSA-2024:4211
  • Red Hat Enterprise Linux BaseOS (v. 9) bpftool 7.3.0-427.42.1.el9_4, kernel 5.14.0-427.42.1.el9_4, kernel-64k 5.14.0-427.42.1.el9_4, kernel-core 5.14.0-427.42.1.el9_4, kernel-tools 5.14.0-427.42.1.el9_4, python3-perf 5.14.0-427.42.1.el9_4, +28 more
    fixed: vendor fix RHSA-2024:8617
  • Red Hat Enterprise Linux BaseOS AUS (v.8.6) perf 4.18.0-372.115.1.el8_6, kernel 4.18.0-372.115.1.el8_6, bpftool 4.18.0-372.115.1.el8_6, kernel-core 4.18.0-372.115.1.el8_6, kernel-tools 4.18.0-372.115.1.el8_6, python3-perf 4.18.0-372.115.1.el8_6, +8 more Red Hat Enterprise Linux BaseOS E4S (v.8.6) perf 4.18.0-372.115.1.el8_6, kernel 4.18.0-372.115.1.el8_6, bpftool 4.18.0-372.115.1.el8_6, kernel-core 4.18.0-372.115.1.el8_6, kernel-tools 4.18.0-372.115.1.el8_6, python3-perf 4.18.0-372.115.1.el8_6, +15 more
    fixed: vendor fix RHSA-2024:5065
show 11 more
  • Red Hat Enterprise Linux BaseOS EUS (v.8.8) perf 4.18.0-477.74.1.el8_8, kernel 4.18.0-477.74.1.el8_8, bpftool 4.18.0-477.74.1.el8_8, kernel-core 4.18.0-477.74.1.el8_8, kernel-tools 4.18.0-477.74.1.el8_8, python3-perf 4.18.0-477.74.1.el8_8, +15 more
    fixed: vendor fix RHSA-2024:6993
  • Red Hat Enterprise Linux BaseOS EUS (v.9.2) bpftool 7.0.0-284.90.1.el9_2, kernel 5.14.0-284.90.1.el9_2, kernel-64k 5.14.0-284.90.1.el9_2, kernel-core 5.14.0-284.90.1.el9_2, kernel-tools 5.14.0-284.90.1.el9_2, python3-perf 5.14.0-284.90.1.el9_2, +28 more
    fixed: vendor fix RHSA-2024:8613
  • Red Hat Enterprise Linux BaseOS TUS (v.8.6) perf 4.18.0-372.115.1.el8_6, kernel 4.18.0-372.115.1.el8_6, bpftool 4.18.0-372.115.1.el8_6, kernel-core 4.18.0-372.115.1.el8_6, kernel-tools 4.18.0-372.115.1.el8_6, python3-perf 4.18.0-372.115.1.el8_6, +8 more
    fixed: vendor fix RHSA-2024:5065
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.8.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.8.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.8.1.el8_10
    fixed: vendor fix RHSA-2024:4211
  • Red Hat Enterprise Linux CRB (v. 9) libperf 5.14.0-427.42.1.el9_4, kernel-debuginfo-common-s390x 5.14.0-427.42.1.el9_4, kernel-debuginfo-common-x86_64 5.14.0-427.42.1.el9_4, kernel-debuginfo-common-aarch64 5.14.0-427.42.1.el9_4, kernel-debuginfo-common-ppc64le 5.14.0-427.42.1.el9_4
    fixed: vendor fix RHSA-2024:8617
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-kvm 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-core 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-modules 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-debug-kvm 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-debug-core 4.18.0-553.8.1.rt7.349.el8_10, +4 more
    fixed: vendor fix RHSA-2024:4352
  • Red Hat Enterprise Linux NFV (v. 9) kernel-rt 5.14.0-427.42.1.el9_4, kernel-rt-kvm 5.14.0-427.42.1.el9_4, kernel-rt-core 5.14.0-427.42.1.el9_4, kernel-rt-modules 5.14.0-427.42.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.42.1.el9_4, kernel-rt-debug-core 5.14.0-427.42.1.el9_4, +6 more
    fixed: vendor fix RHSA-2024:8617
  • Red Hat Enterprise Linux Real Time EUS (v.9.2) kernel-rt 5.14.0-284.90.1.rt14.375.el9_2, kernel-rt-core 5.14.0-284.90.1.rt14.375.el9_2, kernel-rt-modules 5.14.0-284.90.1.rt14.375.el9_2, kernel-rt-debug-core 5.14.0-284.90.1.rt14.375.el9_2, kernel-rt-modules-core 5.14.0-284.90.1.rt14.375.el9_2, kernel-rt-debug-modules 5.14.0-284.90.1.rt14.375.el9_2, +4 more Red Hat Enterprise Linux Real Time for NFV EUS (v.9.2) kernel-rt 5.14.0-284.90.1.rt14.375.el9_2, kernel-rt-kvm 5.14.0-284.90.1.rt14.375.el9_2, kernel-rt-core 5.14.0-284.90.1.rt14.375.el9_2, kernel-rt-modules 5.14.0-284.90.1.rt14.375.el9_2, kernel-rt-debug-kvm 5.14.0-284.90.1.rt14.375.el9_2, kernel-rt-debug-core 5.14.0-284.90.1.rt14.375.el9_2, +6 more
    fixed: vendor fix RHSA-2024:8614
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-core 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-modules 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-debug-core 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-debug-modules 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-modules-extra 4.18.0-553.8.1.rt7.349.el8_10, +2 more
    fixed: vendor fix RHSA-2024:4352
  • Red Hat Enterprise Linux RT (v. 9) kernel-rt 5.14.0-427.42.1.el9_4, kernel-rt-core 5.14.0-427.42.1.el9_4, kernel-rt-modules 5.14.0-427.42.1.el9_4, kernel-rt-debug-core 5.14.0-427.42.1.el9_4, kernel-rt-modules-core 5.14.0-427.42.1.el9_4, kernel-rt-debug-modules 5.14.0-427.42.1.el9_4, +4 more
    fixed: vendor fix RHSA-2024:8617
  • 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 Red Hat Enterprise Linux AppStream EUS (v.9.2) kernel-doc 5.14.0-284.90.1.el9_2 Red Hat Enterprise Linux BaseOS (v. 8) kernel-headers 4.18.0-553.8.1.el8_10, kernel-cross-headers 4.18.0-553.8.1.el8_10
    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
2 y ago

Exploit prediction

0.65% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

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.