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Fencer Intel
high 8.1

CVE-2026-63889 json

scsi: scsi_transport_fc: Widen FPIN pname walker counter to u32

published 3mo ago modified 13d ago also EUVD-2026-45662

cvss
8.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 30%
public exploits
0
none known

Summary

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

scsi: scsi_transport_fc: Widen FPIN pname walker counter to u32

An adjacent Fibre Channel fabric actor that can deliver an FPIN ELS frame to an lpfc or qla2xxx Linux initiator can trigger a non-return in the generic FC transport. This is not a local userspace or IP network path; the attacker must be able to inject fabric traffic, for example as a compromised switch or fabric controller, or as a same-zone N_Port on a fabric that permits source spoofing.

The Link-Integrity and Peer-Congestion FPIN walkers used a u8 loop counter against the 32-bit on-wire pname_count field, and did not bound pname_count by the descriptor body already validated by the TLV walker. A pname_count of 256 therefore wraps the counter and keeps the loop condition true indefinitely.

Factor the shared pname_list[] walk into one helper, widen the counter to u32, and clamp pname_count against the entries that fit in the descriptor body before iterating.

Patch / fix

  • Linux Linux 5.15.210, 6.1.176, 6.6.143, 6.12.93, 6.18.35, 7.0.12, 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-2026-63889

  • linux Ubuntu 22.04 LTS 5.15.0-198.208
  • linux Ubuntu 24.04 LTS 6.8.0-146.146
  • linux Ubuntu 26.04 LTS 7.0.0-28.28
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1117.124
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1066.69
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1009.9
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1118.128
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1070.78

ubuntu advisories UBUNTU-CVE-2026-63889

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 6.12.0-211.55.1.el10_2
  • rv RHEL 10.2 6.12.0-211.55.1.el10_2
  • perf RHEL 10.2 6.12.0-211.55.1.el10_2
  • rtla RHEL 10.2 6.12.0-211.55.1.el10_2
  • libperf RHEL 10.2 6.12.0-211.55.1.el10_2
  • kernel-rt RHEL 10.2 6.12.0-211.55.1.el10_2
  • kernel-64k RHEL 10.2 6.12.0-211.55.1.el10_2
  • kernel-core RHEL 10.2 6.12.0-211.55.1.el10_2

red hat advisories RHSA-2026:67471RHSA-2026:67469RHSA-2026:67468RHSA-2026:67150

  • 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
  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.53.81.1
  • kernel-source SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1
  • kernel-default SLE Workstation Extension 15 SP7, SLE Module for Legacy 15 SP7, SLE Module for Basesystem 15 SP7 +2 more 6.4.0-150700.53.81.1
  • kernel-zfcpdump SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1
  • kernel-obs-build SLE Module for Development Tools 15 SP7 6.4.0-150700.53.81.1
  • kernel-default-base SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1.150700.17.45.1

suse advisories SUSE-SU-2026:4254-1SUSE-SU-2026:23887-1SUSE-SU-2026:23902-1SUSE-SU-2026:23897-1SUSE-SU-2026:23881-1SUSE-SU-2026:4120-1

  • 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 4.18.0-553.163.1.el8_10
  • perf AlmaLinux 8 4.18.0-553.163.1.el8_10
  • bpftool AlmaLinux 8 4.18.0-553.163.1.el8_10
  • kernel-core AlmaLinux 8 4.18.0-553.163.1.el8_10
  • kernel-tools AlmaLinux 8 4.18.0-553.163.1.el8_10
  • python3-perf AlmaLinux 8 4.18.0-553.163.1.el8_10
  • kernel-modules AlmaLinux 8 4.18.0-553.163.1.el8_10
  • kernel-zfcpdump AlmaLinux 8 4.18.0-553.163.1.el8_10

almalinux advisories ALSA-2026:67468ALSA-2026:67469ALSA-2026:67471ALSA-2026:67150

  • kernel Rocky Linux 10 6.12.0-211.55.1.el10_2
  • kernel-rt Rocky Linux 8 4.18.0-553.163.1.rt7.504.el8_10
  • kernel Rocky Linux 8 4.18.0-553.163.1.el8_10
  • kernel Rocky Linux 9 5.14.0-687.47.1.el9_8

rocky linux advisories RLSA-2026:67471RLSA-2026:67469RLSA-2026:67468RLSA-2026:67150

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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-2026-63889 updated cvss 6.5

kernel: scsi: scsi_transport_fc: Widen FPIN pname walker counter to u32

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: workaround, 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: workaround, no fix available
  • Red Hat CodeReady Linux Builder EUS (v.9.6) libperf 5.14.0-570.155.1.el9_6, kernel-debuginfo-common-s390x 5.14.0-570.155.1.el9_6, kernel-debuginfo-common-x86_64 5.14.0-570.155.1.el9_6, kernel-debuginfo-common-aarch64 5.14.0-570.155.1.el9_6, kernel-debuginfo-common-ppc64le 5.14.0-570.155.1.el9_6
    fixed: vendor fix RHSA-2026:98239
  • 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 6.12.0-211.55.1.el10_2, perf 6.12.0-211.55.1.el10_2, rtla 6.12.0-211.55.1.el10_2, python3-perf 6.12.0-211.55.1.el10_2, kernel-devel-matched 6.12.0-211.55.1.el10_2, kernel-64k-devel-matched 6.12.0-211.55.1.el10_2, +7 more
    fixed: vendor fix RHSA-2026:67471
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) rv 5.14.0-427.162.1.el9_4, perf 5.14.0-427.162.1.el9_4, rtla 5.14.0-427.162.1.el9_4, kernel-devel-matched 5.14.0-427.162.1.el9_4, kernel-64k-devel-matched 5.14.0-427.162.1.el9_4, kernel-debug-devel-matched 5.14.0-427.162.1.el9_4, +6 more
    fixed: vendor fix RHSA-2026:98047
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) rv 5.14.0-570.155.1.el9_6, perf 5.14.0-570.155.1.el9_6, rtla 5.14.0-570.155.1.el9_6, python3-perf 5.14.0-570.155.1.el9_6, kernel-devel-matched 5.14.0-570.155.1.el9_6, kernel-64k-devel-matched 5.14.0-570.155.1.el9_6, +7 more
    fixed: vendor fix RHSA-2026:98239
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.163.1.el8_10, kernel 4.18.0-553.163.1.el8_10, bpftool 4.18.0-553.163.1.el8_10, kernel-core 4.18.0-553.163.1.el8_10, kernel-tools 4.18.0-553.163.1.el8_10, python3-perf 4.18.0-553.163.1.el8_10, +15 more
    fixed: vendor fix RHSA-2026:67468
show 18 more
  • 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 6.12.0-211.55.1.el10_2, kernel-64k 6.12.0-211.55.1.el10_2, kernel-core 6.12.0-211.55.1.el10_2, kernel-tools 6.12.0-211.55.1.el10_2, kernel-modules 6.12.0-211.55.1.el10_2, kernel-64k-core 6.12.0-211.55.1.el10_2, +28 more
    fixed: vendor fix RHSA-2026:67471
  • Red Hat Enterprise Linux BaseOS E4S (v.9.4) bpftool 7.3.0-427.162.1.el9_4, kernel 5.14.0-427.162.1.el9_4, kernel-64k 5.14.0-427.162.1.el9_4, kernel-core 5.14.0-427.162.1.el9_4, kernel-tools 5.14.0-427.162.1.el9_4, python3-perf 5.14.0-427.162.1.el9_4, +28 more
    fixed: vendor fix RHSA-2026:98047
  • Red Hat Enterprise Linux BaseOS EUS (v.9.6) kernel 5.14.0-570.155.1.el9_6, kernel-64k 5.14.0-570.155.1.el9_6, kernel-core 5.14.0-570.155.1.el9_6, kernel-tools 5.14.0-570.155.1.el9_6, kernel-modules 5.14.0-570.155.1.el9_6, kernel-64k-core 5.14.0-570.155.1.el9_6, +27 more
    fixed: vendor fix RHSA-2026:98239
  • 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
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.55.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.55.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.55.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.55.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.55.1.el10_2
    fixed: vendor fix RHSA-2026:67471
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.163.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.163.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.163.1.el8_10
    fixed: vendor fix RHSA-2026:67468
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.163.1.rt7.504.el8_10, kernel-rt-kvm 4.18.0-553.163.1.rt7.504.el8_10, kernel-rt-core 4.18.0-553.163.1.rt7.504.el8_10, kernel-rt-modules 4.18.0-553.163.1.rt7.504.el8_10, kernel-rt-debug-kvm 4.18.0-553.163.1.rt7.504.el8_10, kernel-rt-debug-core 4.18.0-553.163.1.rt7.504.el8_10, +4 more
    fixed: vendor fix RHSA-2026:67469
  • 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 6.12.0-211.55.1.el10_2, kernel-rt-64k 6.12.0-211.55.1.el10_2, kernel-rt-core 6.12.0-211.55.1.el10_2, kernel-rt-modules 6.12.0-211.55.1.el10_2, kernel-rt-64k-core 6.12.0-211.55.1.el10_2, kernel-rt-debug-core 6.12.0-211.55.1.el10_2, +14 more
    fixed: vendor fix RHSA-2026:67471
  • Red Hat Enterprise Linux Real Time E4S (v.9.4) kernel-rt 5.14.0-427.162.1.el9_4, kernel-rt-core 5.14.0-427.162.1.el9_4, kernel-rt-modules 5.14.0-427.162.1.el9_4, kernel-rt-debug-core 5.14.0-427.162.1.el9_4, kernel-rt-modules-core 5.14.0-427.162.1.el9_4, kernel-rt-debug-modules 5.14.0-427.162.1.el9_4, +4 more
    fixed: vendor fix RHSA-2026:98047
  • Red Hat Enterprise Linux Real Time EUS (v.9.6) kernel-rt 5.14.0-570.155.1.el9_6, kernel-rt-64k 5.14.0-570.155.1.el9_6, kernel-rt-core 5.14.0-570.155.1.el9_6, kernel-rt-modules 5.14.0-570.155.1.el9_6, kernel-rt-64k-core 5.14.0-570.155.1.el9_6, kernel-rt-debug-core 5.14.0-570.155.1.el9_6, +14 more
    fixed: vendor fix RHSA-2026:98239
  • 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 6.12.0-211.55.1.el10_2, kernel-rt-core 6.12.0-211.55.1.el10_2, kernel-rt-modules 6.12.0-211.55.1.el10_2, kernel-rt-debug-core 6.12.0-211.55.1.el10_2, kernel-rt-modules-core 6.12.0-211.55.1.el10_2, kernel-rt-debug-modules 6.12.0-211.55.1.el10_2, +4 more
    fixed: vendor fix RHSA-2026:67471
  • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4) kernel-rt 5.14.0-427.162.1.el9_4, kernel-rt-kvm 5.14.0-427.162.1.el9_4, kernel-rt-core 5.14.0-427.162.1.el9_4, kernel-rt-modules 5.14.0-427.162.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.162.1.el9_4, kernel-rt-debug-core 5.14.0-427.162.1.el9_4, +6 more
    fixed: vendor fix RHSA-2026:98047
  • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6) kernel-rt 5.14.0-570.155.1.el9_6, kernel-rt-kvm 5.14.0-570.155.1.el9_6, kernel-rt-core 5.14.0-570.155.1.el9_6, kernel-rt-modules 5.14.0-570.155.1.el9_6, kernel-rt-debug-kvm 5.14.0-570.155.1.el9_6, kernel-rt-debug-core 5.14.0-570.155.1.el9_6, +6 more
    fixed: vendor fix RHSA-2026:98239
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.163.1.rt7.504.el8_10, kernel-rt-core 4.18.0-553.163.1.rt7.504.el8_10, kernel-rt-modules 4.18.0-553.163.1.rt7.504.el8_10, kernel-rt-debug-core 4.18.0-553.163.1.rt7.504.el8_10, kernel-rt-debug-modules 4.18.0-553.163.1.rt7.504.el8_10, kernel-rt-modules-extra 4.18.0-553.163.1.rt7.504.el8_10, +2 more
    fixed: vendor fix RHSA-2026:67469
  • 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
26d ago

Exploit prediction

0.36% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 8.1 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
  • CWE-190 Integer Overflow or Wraparound
  • CWE-835 Loop with Unreachable Exit Condition
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.