Skip to content
Fencer Intel
no cvss —

CVE-2026-99284 json

net: skbuff: propagate shared-frag marker in skb_zerocopy()

published 2d ago modified 2d ago also EUVD-2026-119329

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 11%
public exploits
0
none known

Summary

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

net: skbuff: propagate shared-frag marker in skb_zerocopy()

skb_zerocopy() moves frag descriptors from @from into @to and takes a reference on each frag, but it does not copy skb_shinfo(from)->flags into skb_shinfo(to)->flags. A destination skb holding the same page-cache backed frags as the source therefore reports skb_has_shared_frag() as false.

That breaks the invariant relied on by later in-place writers. ESP input checks skb_has_shared_frag() before deciding whether an uncloned nonlinear skb can skip skb_cow_data(); with the marker lost, an skb that skb_zerocopy() built for nfnetlink_queue or for an openvswitch upcall is decrypted in place, letting an unprivileged user write into the page cache of a root-owned read-only file.

Propagate SKBFL_SHARED_FRAG when frag descriptors are copied, as done for the other frag-transfer helpers.

Patch / fix

  • Linux Linux 6.18.61, 7.2.15, 7.3.2, 7.4-rc1
  • linux Debian 13 6.12.115-1
  • linux Debian 14 7.2.14-1

debian advisories DEBIAN-CVE-2026-99284

  • kernel AlmaLinux 8 4.18.0-553.181.1.el8_10
  • perf AlmaLinux 8 4.18.0-553.181.1.el8_10
  • bpftool AlmaLinux 8 4.18.0-553.181.1.el8_10
  • kernel-core AlmaLinux 8 4.18.0-553.181.1.el8_10
  • kernel-tools AlmaLinux 8 4.18.0-553.181.1.el8_10
  • python3-perf AlmaLinux 8 4.18.0-553.181.1.el8_10
  • kernel-modules AlmaLinux 8 4.18.0-553.181.1.el8_10
  • kernel-zfcpdump AlmaLinux 8 4.18.0-553.181.1.el8_10

almalinux advisories ALSA-2026:93436

Is CVE-2026-99284 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.

Check with Fencer

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-2026-99284 updated cvss 7.8

kernel: kernel: privilege escalation via missing shared fragment flag in skb_zerocopy

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: workaround, no fix available
  • 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 “Fix deferred”
  • Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9, openshift/ose-rhel-coreos-10
    affected: workaround, no fix available
  • Red Hat CodeReady Linux Builder EUS (v.9.6) libperf 5.14.0-570.154.1.el9_6, kernel-debuginfo-common-s390x 5.14.0-570.154.1.el9_6, kernel-debuginfo-common-x86_64 5.14.0-570.154.1.el9_6, kernel-debuginfo-common-aarch64 5.14.0-570.154.1.el9_6, kernel-debuginfo-common-ppc64le 5.14.0-570.154.1.el9_6
    fixed: vendor fix RHSA-2026:94438
  • Red Hat Enterprise Linux kernel-modules-internal 6.12.0-211.72.1.el10_2
    fixed: vendor fix RHSA-2026:93413
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.64.1.el9_8, perf 5.14.0-687.64.1.el9_8, rtla 5.14.0-687.64.1.el9_8, python3-perf 5.14.0-687.64.1.el9_8, kernel-devel-matched 5.14.0-687.64.1.el9_8, kernel-64k-devel-matched 5.14.0-687.64.1.el9_8, +7 more
    fixed: vendor fix RHSA-2026:93412
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.72.1.el10_2, perf 6.12.0-211.72.1.el10_2, rtla 6.12.0-211.72.1.el10_2, python3-perf 6.12.0-211.72.1.el10_2, kernel-devel-matched 6.12.0-211.72.1.el10_2, kernel-64k-devel-matched 6.12.0-211.72.1.el10_2, +7 more
    fixed: vendor fix RHSA-2026:93413
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) perf 5.14.0-284.202.1.el9_2, rtla 5.14.0-284.202.1.el9_2, kernel-devel-matched 5.14.0-284.202.1.el9_2, kernel-64k-devel-matched 5.14.0-284.202.1.el9_2, kernel-debug-devel-matched 5.14.0-284.202.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.202.1.el9_2, +5 more
    fixed: vendor fix RHSA-2026:94477
show 31 more
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) rv 5.14.0-427.161.1.el9_4, perf 5.14.0-427.161.1.el9_4, rtla 5.14.0-427.161.1.el9_4, kernel-devel-matched 5.14.0-427.161.1.el9_4, kernel-64k-devel-matched 5.14.0-427.161.1.el9_4, kernel-debug-devel-matched 5.14.0-427.161.1.el9_4, +6 more
    fixed: vendor fix RHSA-2026:94109
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) rv 6.12.0-55.117.1.el10_0, perf 6.12.0-55.117.1.el10_0, rtla 6.12.0-55.117.1.el10_0, python3-perf 6.12.0-55.117.1.el10_0, kernel-devel-matched 6.12.0-55.117.1.el10_0, kernel-64k-devel-matched 6.12.0-55.117.1.el10_0, +7 more
    fixed: vendor fix RHSA-2026:94508
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) rv 5.14.0-570.154.1.el9_6, perf 5.14.0-570.154.1.el9_6, rtla 5.14.0-570.154.1.el9_6, python3-perf 5.14.0-570.154.1.el9_6, kernel-devel-matched 5.14.0-570.154.1.el9_6, kernel-64k-devel-matched 5.14.0-570.154.1.el9_6, +7 more
    fixed: vendor fix RHSA-2026:94438
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.181.1.el8_10, kernel 4.18.0-553.181.1.el8_10, bpftool 4.18.0-553.181.1.el8_10, kernel-core 4.18.0-553.181.1.el8_10, kernel-tools 4.18.0-553.181.1.el8_10, python3-perf 4.18.0-553.181.1.el8_10, +15 more
    fixed: vendor fix RHSA-2026:93436
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.64.1.el9_8, kernel-64k 5.14.0-687.64.1.el9_8, kernel-core 5.14.0-687.64.1.el9_8, kernel-tools 5.14.0-687.64.1.el9_8, kernel-modules 5.14.0-687.64.1.el9_8, kernel-64k-core 5.14.0-687.64.1.el9_8, +27 more
    fixed: vendor fix RHSA-2026:93412
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.72.1.el10_2, kernel-64k 6.12.0-211.72.1.el10_2, kernel-core 6.12.0-211.72.1.el10_2, kernel-tools 6.12.0-211.72.1.el10_2, kernel-modules 6.12.0-211.72.1.el10_2, kernel-64k-core 6.12.0-211.72.1.el10_2, +28 more
    fixed: vendor fix RHSA-2026:93413
  • Red Hat Enterprise Linux BaseOS AUS (v.8.4) perf 4.18.0-305.217.1.el8_4, kernel 4.18.0-305.217.1.el8_4, bpftool 4.18.0-305.217.1.el8_4, kernel-core 4.18.0-305.217.1.el8_4, kernel-tools 4.18.0-305.217.1.el8_4, python3-perf 4.18.0-305.217.1.el8_4, +8 more
    fixed: vendor fix RHSA-2026:94596
  • Red Hat Enterprise Linux BaseOS AUS (v.8.6) perf 4.18.0-372.227.1.el8_6, kernel 4.18.0-372.227.1.el8_6, bpftool 4.18.0-372.227.1.el8_6, kernel-core 4.18.0-372.227.1.el8_6, kernel-tools 4.18.0-372.227.1.el8_6, python3-perf 4.18.0-372.227.1.el8_6, +8 more
    fixed: vendor fix RHSA-2026:94996
  • Red Hat Enterprise Linux BaseOS E4S (v.8.8) perf 4.18.0-477.178.1.el8_8, kernel 4.18.0-477.178.1.el8_8, bpftool 4.18.0-477.178.1.el8_8, kernel-core 4.18.0-477.178.1.el8_8, kernel-tools 4.18.0-477.178.1.el8_8, python3-perf 4.18.0-477.178.1.el8_8, +9 more
    fixed: vendor fix RHSA-2026:94303
  • Red Hat Enterprise Linux BaseOS E4S (v.9.2) bpftool 7.0.0-284.202.1.el9_2, kernel 5.14.0-284.202.1.el9_2, kernel-64k 5.14.0-284.202.1.el9_2, kernel-core 5.14.0-284.202.1.el9_2, kernel-tools 5.14.0-284.202.1.el9_2, python3-perf 5.14.0-284.202.1.el9_2, +28 more
    fixed: vendor fix RHSA-2026:94477
  • Red Hat Enterprise Linux BaseOS E4S (v.9.4) bpftool 7.3.0-427.161.1.el9_4, kernel 5.14.0-427.161.1.el9_4, kernel-64k 5.14.0-427.161.1.el9_4, kernel-core 5.14.0-427.161.1.el9_4, kernel-tools 5.14.0-427.161.1.el9_4, python3-perf 5.14.0-427.161.1.el9_4, +28 more
    fixed: vendor fix RHSA-2026:94109
  • Red Hat Enterprise Linux BaseOS EUS (v. 10.0) kernel 6.12.0-55.117.1.el10_0, kernel-64k 6.12.0-55.117.1.el10_0, kernel-core 6.12.0-55.117.1.el10_0, kernel-tools 6.12.0-55.117.1.el10_0, kernel-modules 6.12.0-55.117.1.el10_0, kernel-64k-core 6.12.0-55.117.1.el10_0, +27 more
    fixed: vendor fix RHSA-2026:94508
  • Red Hat Enterprise Linux BaseOS EUS (v.9.6) kernel 5.14.0-570.154.1.el9_6, kernel-64k 5.14.0-570.154.1.el9_6, kernel-core 5.14.0-570.154.1.el9_6, kernel-tools 5.14.0-570.154.1.el9_6, kernel-modules 5.14.0-570.154.1.el9_6, kernel-64k-core 5.14.0-570.154.1.el9_6, +27 more
    fixed: vendor fix RHSA-2026:94438
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) perf 4.18.0-305.217.1.el8_4, kernel 4.18.0-305.217.1.el8_4, bpftool 4.18.0-305.217.1.el8_4, kernel-core 4.18.0-305.217.1.el8_4, kernel-tools 4.18.0-305.217.1.el8_4, python3-perf 4.18.0-305.217.1.el8_4, +8 more
    fixed: vendor fix RHSA-2026:94596
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) perf 4.18.0-372.227.1.el8_6, kernel 4.18.0-372.227.1.el8_6, bpftool 4.18.0-372.227.1.el8_6, kernel-core 4.18.0-372.227.1.el8_6, kernel-tools 4.18.0-372.227.1.el8_6, python3-perf 4.18.0-372.227.1.el8_6, +8 more
    fixed: vendor fix RHSA-2026:94996
  • Red Hat Enterprise Linux BaseOS TUS (v.8.8) perf 4.18.0-477.178.1.el8_8, kernel 4.18.0-477.178.1.el8_8, bpftool 4.18.0-477.178.1.el8_8, kernel-core 4.18.0-477.178.1.el8_8, kernel-tools 4.18.0-477.178.1.el8_8, python3-perf 4.18.0-477.178.1.el8_8, +8 more
    fixed: vendor fix RHSA-2026:94303
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.64.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.64.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.64.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.64.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.64.1.el9_8
    fixed: vendor fix RHSA-2026:93412
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.72.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.72.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.72.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.72.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.72.1.el10_2
    fixed: vendor fix RHSA-2026:93413
  • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) libperf 6.12.0-55.117.1.el10_0, kernel-debuginfo-common-s390x 6.12.0-55.117.1.el10_0, kernel-debuginfo-common-x86_64 6.12.0-55.117.1.el10_0, kernel-debuginfo-common-aarch64 6.12.0-55.117.1.el10_0, kernel-debuginfo-common-ppc64le 6.12.0-55.117.1.el10_0
    fixed: vendor fix RHSA-2026:94508
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.181.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.181.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.181.1.el8_10
    fixed: vendor fix RHSA-2026:93436
  • Red Hat Enterprise Linux for Real Time (v. 7 ELS) kernel-rt 3.10.0-1160.169.1.rt56.1321.el7, kernel-rt-trace 3.10.0-1160.169.1.rt56.1321.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.169.1.rt56.1321.el7
    fixed: vendor fix RHSA-2026:95721
  • Red Hat Enterprise Linux Hidden (v. 10) kernel-modules-internal 6.12.0-211.72.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.72.1.el10_2
    fixed: vendor fix RHSA-2026:93413
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.181.1.rt7.522.el8_10, kernel-rt-kvm 4.18.0-553.181.1.rt7.522.el8_10, kernel-rt-core 4.18.0-553.181.1.rt7.522.el8_10, kernel-rt-modules 4.18.0-553.181.1.rt7.522.el8_10, kernel-rt-debug-kvm 4.18.0-553.181.1.rt7.522.el8_10, kernel-rt-debug-core 4.18.0-553.181.1.rt7.522.el8_10, +4 more
    fixed: vendor fix RHSA-2026:93437
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.64.1.el9_8, kernel-rt-64k 5.14.0-687.64.1.el9_8, kernel-rt-core 5.14.0-687.64.1.el9_8, kernel-rt-modules 5.14.0-687.64.1.el9_8, kernel-rt-64k-core 5.14.0-687.64.1.el9_8, kernel-rt-debug-core 5.14.0-687.64.1.el9_8, +14 more
    fixed: vendor fix RHSA-2026:93412
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.72.1.el10_2, kernel-rt-64k 6.12.0-211.72.1.el10_2, kernel-rt-core 6.12.0-211.72.1.el10_2, kernel-rt-modules 6.12.0-211.72.1.el10_2, kernel-rt-64k-core 6.12.0-211.72.1.el10_2, kernel-rt-debug-core 6.12.0-211.72.1.el10_2, +14 more
    fixed: vendor fix RHSA-2026:93413
  • Red Hat Enterprise Linux Real Time E4S (v.9.2) kernel-rt 5.14.0-284.202.1.rt14.487.el9_2, kernel-rt-core 5.14.0-284.202.1.rt14.487.el9_2, kernel-rt-modules 5.14.0-284.202.1.rt14.487.el9_2, kernel-rt-debug-core 5.14.0-284.202.1.rt14.487.el9_2, kernel-rt-modules-core 5.14.0-284.202.1.rt14.487.el9_2, kernel-rt-debug-modules 5.14.0-284.202.1.rt14.487.el9_2, +4 more
    fixed: vendor fix RHSA-2026:94558
  • Red Hat Enterprise Linux Real Time E4S (v.9.4) kernel-rt 5.14.0-427.161.1.el9_4, kernel-rt-core 5.14.0-427.161.1.el9_4, kernel-rt-modules 5.14.0-427.161.1.el9_4, kernel-rt-debug-core 5.14.0-427.161.1.el9_4, kernel-rt-modules-core 5.14.0-427.161.1.el9_4, kernel-rt-debug-modules 5.14.0-427.161.1.el9_4, +4 more
    fixed: vendor fix RHSA-2026:94109
  • Red Hat Enterprise Linux Real Time EUS (v. 10.0) kernel-rt 6.12.0-55.117.1.el10_0, kernel-rt-64k 6.12.0-55.117.1.el10_0, kernel-rt-core 6.12.0-55.117.1.el10_0, kernel-rt-modules 6.12.0-55.117.1.el10_0, kernel-rt-64k-core 6.12.0-55.117.1.el10_0, kernel-rt-debug-core 6.12.0-55.117.1.el10_0, +14 more
    fixed: vendor fix RHSA-2026:94508
  • Red Hat Enterprise Linux Real Time EUS (v.9.6) kernel-rt 5.14.0-570.154.1.el9_6, kernel-rt-64k 5.14.0-570.154.1.el9_6, kernel-rt-core 5.14.0-570.154.1.el9_6, kernel-rt-modules 5.14.0-570.154.1.el9_6, kernel-rt-64k-core 5.14.0-570.154.1.el9_6, kernel-rt-debug-core 5.14.0-570.154.1.el9_6, +14 more
    fixed: vendor fix RHSA-2026:94438
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.64.1.el9_8, kernel-rt-core 5.14.0-687.64.1.el9_8, kernel-rt-modules 5.14.0-687.64.1.el9_8, kernel-rt-debug-core 5.14.0-687.64.1.el9_8, kernel-rt-modules-core 5.14.0-687.64.1.el9_8, kernel-rt-debug-modules 5.14.0-687.64.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:93412
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.72.1.el10_2, kernel-rt-core 6.12.0-211.72.1.el10_2, kernel-rt-modules 6.12.0-211.72.1.el10_2, kernel-rt-debug-core 6.12.0-211.72.1.el10_2, kernel-rt-modules-core 6.12.0-211.72.1.el10_2, kernel-rt-debug-modules 6.12.0-211.72.1.el10_2, +4 more
    fixed: vendor fix RHSA-2026:93413

7 more fixed in the full advisory

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

0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-09).

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.