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Fencer Intel
high 7.8

CVE-2026-98318 json

smb: client: validate absolute native symlink targets before NT fixups

published last mo. modified 24d ago also EUVD-2026-93303

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 1%
public exploits
0
none known

Summary

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

smb: client: validate absolute native symlink targets before NT fixups

With symlinkroot unset, an absolute target is copied without conversion to an NT drive path. Later code still assumes an NT prefix is present when modifying the target and calculating the print name length.

For "/ab", this causes two failures: sym[5] and path[5] are written past their allocations, and plen -= 2 * poff subtracts an assumed 8-byte prefix from a 6-byte UTF-16 target, wrapping u16 plen to 65534. That underflow causes another overflow: memcpy() copies 65534 bytes into a 24-byte buffer. A user with write access to a mounted share can trigger these bugs with default settings.

Validate the NT drive prefix, including an ASCII drive letter, before accessing fixed offsets or subtracting the prefix length.

Patch / fix

  • Linux Linux 6.16, 7.3
  • linux Debian 14 7.2.8-1

debian advisories DEBIAN-CVE-2026-98318

  • linux Ubuntu 26.04 LTS 7.0.0-42.42
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1016.17
  • linux-gcp Ubuntu 26.04 LTS 7.0.0-1016.18
  • linux-ibm Ubuntu 26.04 LTS 7.0.0-1017.17
  • linux-riscv Ubuntu 26.04 LTS 7.0.0-42.42.1
  • linux-oracle Ubuntu 26.04 LTS 7.0.0-1015.16
  • linux-hwe-7.0 Ubuntu 24.04 LTS 7.0.0-42.42~24.04.1
  • linux-oem-7.0 Ubuntu 26.04 LTS 7.0.0-1017.17

ubuntu advisories UBUNTU-CVE-2026-98318

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-source openSUSE Tumbleweed 7.2.10-1.1

opensuse advisories openSUSE-SU-2026:12131-1

Is CVE-2026-98318 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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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-2026-98318 updated cvss 7.0

kernel: smb: client: validate absolute native symlink targets before NT fixups

  • Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    affected: workaround, no fix available
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-741.22.1.el9_9, perf 5.14.0-741.22.1.el9_9, rtla 5.14.0-741.22.1.el9_9, python3-perf 5.14.0-741.22.1.el9_9, kernel-devel-matched 5.14.0-741.22.1.el9_9, kernel-64k-devel-matched 5.14.0-741.22.1.el9_9, +7 more
    fixed: vendor fix RHSA-2026:99135
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-264.16.1.el10_3, perf 6.12.0-264.16.1.el10_3, rtla 6.12.0-264.16.1.el10_3, python3-perf 6.12.0-264.16.1.el10_3, kernel-devel-matched 6.12.0-264.16.1.el10_3, kernel-64k-devel-matched 6.12.0-264.16.1.el10_3, +7 more
    fixed: vendor fix RHSA-2026:99133
  • Red Hat Enterprise Linux AppStream EUS (v.9.8) rv 5.14.0-687.67.1.el9_8, perf 5.14.0-687.67.1.el9_8, rtla 5.14.0-687.67.1.el9_8, python3-perf 5.14.0-687.67.1.el9_8, kernel-devel-matched 5.14.0-687.67.1.el9_8, kernel-64k-devel-matched 5.14.0-687.67.1.el9_8, +7 more
    fixed: vendor fix RHSA-2026:99148
  • Red Hat Enterprise Linux AppStream EUS (v.10.2) rv 6.12.0-211.75.1.el10_2, perf 6.12.0-211.75.1.el10_2, rtla 6.12.0-211.75.1.el10_2, python3-perf 6.12.0-211.75.1.el10_2, kernel-devel-matched 6.12.0-211.75.1.el10_2, kernel-64k-devel-matched 6.12.0-211.75.1.el10_2, +7 more
    fixed: vendor fix RHSA-2026:99139
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-741.22.1.el9_9, kernel-64k 5.14.0-741.22.1.el9_9, kernel-core 5.14.0-741.22.1.el9_9, kernel-tools 5.14.0-741.22.1.el9_9, kernel-modules 5.14.0-741.22.1.el9_9, kernel-64k-core 5.14.0-741.22.1.el9_9, +27 more
    fixed: vendor fix RHSA-2026:99135
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-264.16.1.el10_3, kernel-64k 6.12.0-264.16.1.el10_3, kernel-core 6.12.0-264.16.1.el10_3, kernel-tools 6.12.0-264.16.1.el10_3, kernel-modules 6.12.0-264.16.1.el10_3, kernel-64k-core 6.12.0-264.16.1.el10_3, +28 more
    fixed: vendor fix RHSA-2026:99133
  • Red Hat Enterprise Linux BaseOS EUS (v.9.8) kernel 5.14.0-687.67.1.el9_8, kernel-64k 5.14.0-687.67.1.el9_8, kernel-core 5.14.0-687.67.1.el9_8, kernel-tools 5.14.0-687.67.1.el9_8, kernel-modules 5.14.0-687.67.1.el9_8, kernel-64k-core 5.14.0-687.67.1.el9_8, +27 more
    fixed: vendor fix RHSA-2026:99148
show 14 more
  • Red Hat Enterprise Linux BaseOS EUS (v.10.2) kernel 6.12.0-211.75.1.el10_2, kernel-64k 6.12.0-211.75.1.el10_2, kernel-core 6.12.0-211.75.1.el10_2, kernel-tools 6.12.0-211.75.1.el10_2, kernel-modules 6.12.0-211.75.1.el10_2, kernel-64k-core 6.12.0-211.75.1.el10_2, +28 more
    fixed: vendor fix RHSA-2026:99139
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-741.22.1.el9_9, kernel-debuginfo-common-s390x 5.14.0-741.22.1.el9_9, kernel-debuginfo-common-x86_64 5.14.0-741.22.1.el9_9, kernel-debuginfo-common-aarch64 5.14.0-741.22.1.el9_9, kernel-debuginfo-common-ppc64le 5.14.0-741.22.1.el9_9
    fixed: vendor fix RHSA-2026:99135
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-264.16.1.el10_3, kernel-debuginfo-common-s390x 6.12.0-264.16.1.el10_3, kernel-debuginfo-common-x86_64 6.12.0-264.16.1.el10_3, kernel-debuginfo-common-aarch64 6.12.0-264.16.1.el10_3, kernel-debuginfo-common-ppc64le 6.12.0-264.16.1.el10_3
    fixed: vendor fix RHSA-2026:99133
  • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v.9.8) libperf 5.14.0-687.67.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.67.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.67.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.67.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.67.1.el9_8
    fixed: vendor fix RHSA-2026:99148
  • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v.10.2) libperf 6.12.0-211.75.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.75.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.75.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.75.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.75.1.el10_2
    fixed: vendor fix RHSA-2026:99139
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-741.22.1.el9_9, kernel-rt-64k 5.14.0-741.22.1.el9_9, kernel-rt-core 5.14.0-741.22.1.el9_9, kernel-rt-modules 5.14.0-741.22.1.el9_9, kernel-rt-64k-core 5.14.0-741.22.1.el9_9, kernel-rt-debug-core 5.14.0-741.22.1.el9_9, +14 more
    fixed: vendor fix RHSA-2026:99135
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-264.16.1.el10_3, kernel-rt-64k 6.12.0-264.16.1.el10_3, kernel-rt-core 6.12.0-264.16.1.el10_3, kernel-rt-modules 6.12.0-264.16.1.el10_3, kernel-rt-64k-core 6.12.0-264.16.1.el10_3, kernel-rt-debug-core 6.12.0-264.16.1.el10_3, +14 more
    fixed: vendor fix RHSA-2026:99133
  • Red Hat Enterprise Linux Real Time EUS (v.9.8) kernel-rt 5.14.0-687.67.1.el9_8, kernel-rt-64k 5.14.0-687.67.1.el9_8, kernel-rt-core 5.14.0-687.67.1.el9_8, kernel-rt-modules 5.14.0-687.67.1.el9_8, kernel-rt-64k-core 5.14.0-687.67.1.el9_8, kernel-rt-debug-core 5.14.0-687.67.1.el9_8, +14 more
    fixed: vendor fix RHSA-2026:99148
  • Red Hat Enterprise Linux Real Time EUS (v.10.2) kernel-rt 6.12.0-211.75.1.el10_2, kernel-rt-64k 6.12.0-211.75.1.el10_2, kernel-rt-core 6.12.0-211.75.1.el10_2, kernel-rt-modules 6.12.0-211.75.1.el10_2, kernel-rt-64k-core 6.12.0-211.75.1.el10_2, kernel-rt-debug-core 6.12.0-211.75.1.el10_2, +14 more
    fixed: vendor fix RHSA-2026:99139
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-741.22.1.el9_9, kernel-rt-core 5.14.0-741.22.1.el9_9, kernel-rt-modules 5.14.0-741.22.1.el9_9, kernel-rt-debug-core 5.14.0-741.22.1.el9_9, kernel-rt-modules-core 5.14.0-741.22.1.el9_9, kernel-rt-debug-modules 5.14.0-741.22.1.el9_9, +5 more
    fixed: vendor fix RHSA-2026:99135
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-264.16.1.el10_3, kernel-rt-core 6.12.0-264.16.1.el10_3, kernel-rt-modules 6.12.0-264.16.1.el10_3, kernel-rt-debug-core 6.12.0-264.16.1.el10_3, kernel-rt-modules-core 6.12.0-264.16.1.el10_3, kernel-rt-debug-modules 6.12.0-264.16.1.el10_3, +5 more
    fixed: vendor fix RHSA-2026:99133
  • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.8) kernel-rt 5.14.0-687.67.1.el9_8, kernel-rt-core 5.14.0-687.67.1.el9_8, kernel-rt-modules 5.14.0-687.67.1.el9_8, kernel-rt-debug-core 5.14.0-687.67.1.el9_8, kernel-rt-modules-core 5.14.0-687.67.1.el9_8, kernel-rt-debug-modules 5.14.0-687.67.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:99148
  • Red Hat Enterprise Linux Real Time for NFV EUS (v.10.2) kernel-rt 6.12.0-211.75.1.el10_2, kernel-rt-core 6.12.0-211.75.1.el10_2, kernel-rt-modules 6.12.0-211.75.1.el10_2, kernel-rt-debug-core 6.12.0-211.75.1.el10_2, kernel-rt-modules-core 6.12.0-211.75.1.el10_2, kernel-rt-debug-modules 6.12.0-211.75.1.el10_2, +4 more
    fixed: vendor fix RHSA-2026:99139
  • 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 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 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 Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8
    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

Exploit prediction

0.12% chance of exploitation in the next 30 days, higher than 1% of all scored CVEs (FIRST EPSS, 2026-11-11).

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

Classification

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.