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Fencer Vulns
critical 9.1

CVE-2026-64320 in the critical feed json

nvmet: fix pre-auth out-of-bounds heap read in Discovery Get Log Page

published 2026-07-25 3 mo ago modified 2026-10-30 9 d ago also EUVD-2026-49032

cvss
9.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 56%
public exploits
0
none known

Summary

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

nvmet: fix pre-auth out-of-bounds heap read in Discovery Get Log Page

nvmet_execute_disc_get_log_page() validates only the dword alignment of the host-supplied Log Page Offset (lpo). The 64-bit offset is then added to a small kzalloc'd buffer that holds the discovery log page and the result is passed straight to nvmet_copy_to_sgl(), which memcpy()s data_len bytes out to the host with no source-side bound check:

u64 offset = nvmet_get_log_page_offset(req->cmd); /* 64-bit host */ size_t data_len = nvmet_get_log_page_len(req->cmd); /* 32-bit host */ ... if (offset & 0x3) { ... } /* only check */ ... alloc_len = sizeof(*hdr) + entry_size * discovery_log_entries(req); buffer = kzalloc(alloc_len, GFP_KERNEL); ... status = nvmet_copy_to_sgl(req, 0, buffer + offset, data_len);

The Discovery controller is unauthenticated -- nvmet_host_allowed() returns true unconditionally for the discovery subsystem -- so the call is reachable pre-authentication by any TCP/RDMA/FC peer that can reach the nvmet target. With a discovery log page of ~1 KiB, an attacker requesting up to 4 KiB starting at offset == alloc_len reads the next slab page out and gets its content returned over the fabric (an empirical run on a default nvmet-tcp loopback target leaked 81 canonical kernel pointers in one Get Log Page response). Pointing the offset at unmapped kernel memory faults the in-kernel memcpy and crashes (or panics, on panic_on_oops=1) the target host instead.

The attacker-controlled source-side offset pattern "nvmet_copy_to_sgl(req, 0, buffer + ATTACKER_OFFSET, ...)" is unique to nvmet_execute_disc_get_log_page in the entire nvmet codebase: every other Get Log Page handler in admin-cmd.c either ignores lpo (and silently starts every response at offset 0) or tracks a local destination offset with a fixed source pointer.

Validate the host-supplied offset against the log page size, cap the copy length to what is actually available, and zero-fill any remainder of the host transfer buffer. The zero-fill matches the existing short-response pattern in nvmet_execute_get_log_changed_ns() (admin-cmd.c) and prevents leaking transport SGL contents when the host asks for more bytes than the log page contains.

Patch / fix

  • Linux Linux 6.1.191, 6.6.160, 6.12.96, 6.18.39, 7.1.4, 7.2
  • linux Debian 13 6.12.96-1
  • linux Debian 14 7.1.4-1
  • linux-6.12 Debian 12 6.12.100-1~deb12u1

debian advisories DEBIAN-CVE-2026-64320

  • linux Ubuntu 24.04 LTS 6.8.0-147.147
  • linux Ubuntu 26.04 LTS 7.0.0-31.31
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1067.70
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1012.12
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1071.79
  • linux-gcp Ubuntu 26.04 LTS 7.0.0-1011.11
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1066.74
  • linux-gke Ubuntu 26.04 LTS 7.0.0-1006.7

ubuntu advisories UBUNTU-CVE-2026-64320

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 5.14.0-687.45.1.el9_8
  • rv RHEL 9 5.14.0-687.45.1.el9_8
  • perf RHEL 9 5.14.0-687.45.1.el9_8
  • rtla RHEL 9 5.14.0-687.45.1.el9_8
  • libperf RHEL 9 5.14.0-687.45.1.el9_8
  • kernel-rt RHEL 9 5.14.0-687.45.1.el9_8
  • kernel-64k RHEL 9 5.14.0-687.45.1.el9_8
  • kernel-core RHEL 9 5.14.0-687.45.1.el9_8

red hat advisories RHSA-2026:79782RHSA-2026:77216RHSA-2026:64808RHSA-2026:61887RHSA-2026:59737RHSA-2026:59821

  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.84.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.84.1
  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.53.84.1
  • kernel-source SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 6.4.0-150700.53.84.1
  • kernel-default SLE Workstation Extension 15 SP7, SLE Module for Legacy 15 SP7, SLE Module for Basesystem 15 SP7 +2 more 6.4.0-150700.53.84.1
  • kernel-zfcpdump SLE Module for Basesystem 15 SP7 6.4.0-150700.53.84.1
  • kernel-obs-build SLE Module for Development Tools 15 SP7 6.4.0-150700.53.84.1
  • kernel-default-base SLE Module for Basesystem 15 SP7 6.4.0-150700.53.84.1.150700.17.47.1

suse advisories SUSE-SU-2026:4706-1SUSE-SU-2026:4687-1SUSE-SU-2026:4660-1SUSE-SU-2026:4640-1SUSE-SU-2026:24316-1SUSE-SU-2026:24315-1

  • 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-2026:21910-1openSUSE-SU-2026:11476-1

  • kernel AlmaLinux 9 5.14.0-687.45.1.el9_8
  • rv AlmaLinux 9 5.14.0-687.45.1.el9_8
  • perf AlmaLinux 9 5.14.0-687.45.1.el9_8
  • rtla AlmaLinux 9 5.14.0-687.45.1.el9_8
  • libperf AlmaLinux 9 5.14.0-687.45.1.el9_8
  • kernel-rt AlmaLinux 9 5.14.0-687.45.1.el9_8
  • kernel-64k AlmaLinux 9 5.14.0-687.45.1.el9_8
  • kernel-core AlmaLinux 9 5.14.0-687.45.1.el9_8

almalinux advisories ALSA-2026:64808ALSA-2026:61887ALSA-2026:59737ALSA-2026:59821

  • kernel Rocky Linux 9 5.14.0-687.45.1.el9_8
  • kernel Rocky Linux 10 6.12.0-211.50.1.el10_2
  • kernel-rt Rocky Linux 8 4.18.0-553.158.1.rt7.499.el8_10
  • kernel Rocky Linux 8 4.18.0-553.158.1.el8_10

rocky linux advisories RLSA-2026:64808RLSA-2026:61887RLSA-2026:59737RLSA-2026:59821

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-2026-64320 updated cvss 7.0

kernel: nvmet: fix pre-auth out-of-bounds heap read in Discovery Get Log Page

  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 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
    affected: no fix available
  • Red Hat CodeReady Linux Builder EUS (v.9.6) libperf 5.14.0-570.152.1.el9_6, kernel-debuginfo-common-s390x 5.14.0-570.152.1.el9_6, kernel-debuginfo-common-x86_64 5.14.0-570.152.1.el9_6, kernel-debuginfo-common-aarch64 5.14.0-570.152.1.el9_6, kernel-debuginfo-common-ppc64le 5.14.0-570.152.1.el9_6
    fixed: vendor fix RHSA-2026:91492
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.45.1.el9_8, perf 5.14.0-687.45.1.el9_8, rtla 5.14.0-687.45.1.el9_8, python3-perf 5.14.0-687.45.1.el9_8, kernel-devel-matched 5.14.0-687.45.1.el9_8, kernel-64k-devel-matched 5.14.0-687.45.1.el9_8, +7 more
    fixed: vendor fix RHSA-2026:64808
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.50.1.el10_2, perf 6.12.0-211.50.1.el10_2, rtla 6.12.0-211.50.1.el10_2, python3-perf 6.12.0-211.50.1.el10_2, kernel-devel-matched 6.12.0-211.50.1.el10_2, kernel-64k-devel-matched 6.12.0-211.50.1.el10_2, +7 more
    fixed: vendor fix RHSA-2026:61887
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) rv 5.14.0-570.152.1.el9_6, perf 5.14.0-570.152.1.el9_6, rtla 5.14.0-570.152.1.el9_6, python3-perf 5.14.0-570.152.1.el9_6, kernel-devel-matched 5.14.0-570.152.1.el9_6, kernel-64k-devel-matched 5.14.0-570.152.1.el9_6, +7 more
    fixed: vendor fix RHSA-2026:91492
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.158.1.el8_10, kernel 4.18.0-553.158.1.el8_10, bpftool 4.18.0-553.158.1.el8_10, kernel-core 4.18.0-553.158.1.el8_10, kernel-tools 4.18.0-553.158.1.el8_10, python3-perf 4.18.0-553.158.1.el8_10, +15 more
    fixed: vendor fix RHSA-2026:59821
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.45.1.el9_8, kernel-64k 5.14.0-687.45.1.el9_8, kernel-core 5.14.0-687.45.1.el9_8, kernel-tools 5.14.0-687.45.1.el9_8, kernel-modules 5.14.0-687.45.1.el9_8, kernel-64k-core 5.14.0-687.45.1.el9_8, +27 more
    fixed: vendor fix RHSA-2026:64808
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.50.1.el10_2, kernel-64k 6.12.0-211.50.1.el10_2, kernel-core 6.12.0-211.50.1.el10_2, kernel-tools 6.12.0-211.50.1.el10_2, kernel-modules 6.12.0-211.50.1.el10_2, kernel-64k-core 6.12.0-211.50.1.el10_2, +28 more
    fixed: vendor fix RHSA-2026:61887
show 19 more
  • Red Hat Enterprise Linux BaseOS AUS (v.8.4) perf 4.18.0-305.216.1.el8_4, kernel 4.18.0-305.216.1.el8_4, bpftool 4.18.0-305.216.1.el8_4, kernel-core 4.18.0-305.216.1.el8_4, kernel-tools 4.18.0-305.216.1.el8_4, python3-perf 4.18.0-305.216.1.el8_4, +8 more
    fixed: vendor fix RHSA-2026:91585
  • Red Hat Enterprise Linux BaseOS AUS (v.8.6) perf 4.18.0-372.220.1.el8_6, kernel 4.18.0-372.220.1.el8_6, bpftool 4.18.0-372.220.1.el8_6, kernel-core 4.18.0-372.220.1.el8_6, kernel-tools 4.18.0-372.220.1.el8_6, python3-perf 4.18.0-372.220.1.el8_6, +8 more
    fixed: vendor fix RHSA-2026:77216
  • Red Hat Enterprise Linux BaseOS E4S (v.8.8) perf 4.18.0-477.174.1.el8_8, kernel 4.18.0-477.174.1.el8_8, bpftool 4.18.0-477.174.1.el8_8, kernel-core 4.18.0-477.174.1.el8_8, kernel-tools 4.18.0-477.174.1.el8_8, python3-perf 4.18.0-477.174.1.el8_8, +9 more
    fixed: vendor fix RHSA-2026:79782
  • Red Hat Enterprise Linux BaseOS EUS (v.9.6) kernel 5.14.0-570.152.1.el9_6, kernel-64k 5.14.0-570.152.1.el9_6, kernel-core 5.14.0-570.152.1.el9_6, kernel-tools 5.14.0-570.152.1.el9_6, kernel-modules 5.14.0-570.152.1.el9_6, kernel-64k-core 5.14.0-570.152.1.el9_6, +27 more
    fixed: vendor fix RHSA-2026:91492
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) perf 4.18.0-305.216.1.el8_4, kernel 4.18.0-305.216.1.el8_4, bpftool 4.18.0-305.216.1.el8_4, kernel-core 4.18.0-305.216.1.el8_4, kernel-tools 4.18.0-305.216.1.el8_4, python3-perf 4.18.0-305.216.1.el8_4, +8 more
    fixed: vendor fix RHSA-2026:91585
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) perf 4.18.0-372.220.1.el8_6, kernel 4.18.0-372.220.1.el8_6, bpftool 4.18.0-372.220.1.el8_6, kernel-core 4.18.0-372.220.1.el8_6, kernel-tools 4.18.0-372.220.1.el8_6, python3-perf 4.18.0-372.220.1.el8_6, +15 more
    fixed: vendor fix RHSA-2026:77216
  • Red Hat Enterprise Linux BaseOS TUS (v.8.8) perf 4.18.0-477.174.1.el8_8, kernel 4.18.0-477.174.1.el8_8, bpftool 4.18.0-477.174.1.el8_8, kernel-core 4.18.0-477.174.1.el8_8, kernel-tools 4.18.0-477.174.1.el8_8, python3-perf 4.18.0-477.174.1.el8_8, +8 more
    fixed: vendor fix RHSA-2026:79782
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.45.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.45.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.45.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.45.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.45.1.el9_8
    fixed: vendor fix RHSA-2026:64808
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.50.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.50.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.50.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.50.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.50.1.el10_2
    fixed: vendor fix RHSA-2026:61887
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.158.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.158.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.158.1.el8_10
    fixed: vendor fix RHSA-2026:59821
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.158.1.rt7.499.el8_10, kernel-rt-kvm 4.18.0-553.158.1.rt7.499.el8_10, kernel-rt-core 4.18.0-553.158.1.rt7.499.el8_10, kernel-rt-modules 4.18.0-553.158.1.rt7.499.el8_10, kernel-rt-debug-kvm 4.18.0-553.158.1.rt7.499.el8_10, kernel-rt-debug-core 4.18.0-553.158.1.rt7.499.el8_10, +4 more
    fixed: vendor fix RHSA-2026:59737
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.45.1.el9_8, kernel-rt-64k 5.14.0-687.45.1.el9_8, kernel-rt-core 5.14.0-687.45.1.el9_8, kernel-rt-modules 5.14.0-687.45.1.el9_8, kernel-rt-64k-core 5.14.0-687.45.1.el9_8, kernel-rt-debug-core 5.14.0-687.45.1.el9_8, +14 more
    fixed: vendor fix RHSA-2026:64808
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.50.1.el10_2, kernel-rt-64k 6.12.0-211.50.1.el10_2, kernel-rt-core 6.12.0-211.50.1.el10_2, kernel-rt-modules 6.12.0-211.50.1.el10_2, kernel-rt-64k-core 6.12.0-211.50.1.el10_2, kernel-rt-debug-core 6.12.0-211.50.1.el10_2, +14 more
    fixed: vendor fix RHSA-2026:61887
  • Red Hat Enterprise Linux Real Time EUS (v.9.6) kernel-rt 5.14.0-570.152.1.el9_6, kernel-rt-64k 5.14.0-570.152.1.el9_6, kernel-rt-core 5.14.0-570.152.1.el9_6, kernel-rt-modules 5.14.0-570.152.1.el9_6, kernel-rt-64k-core 5.14.0-570.152.1.el9_6, kernel-rt-debug-core 5.14.0-570.152.1.el9_6, +14 more
    fixed: vendor fix RHSA-2026:91492
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.45.1.el9_8, kernel-rt-core 5.14.0-687.45.1.el9_8, kernel-rt-modules 5.14.0-687.45.1.el9_8, kernel-rt-debug-core 5.14.0-687.45.1.el9_8, kernel-rt-modules-core 5.14.0-687.45.1.el9_8, kernel-rt-debug-modules 5.14.0-687.45.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:64808
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.50.1.el10_2, kernel-rt-core 6.12.0-211.50.1.el10_2, kernel-rt-modules 6.12.0-211.50.1.el10_2, kernel-rt-debug-core 6.12.0-211.50.1.el10_2, kernel-rt-modules-core 6.12.0-211.50.1.el10_2, kernel-rt-debug-modules 6.12.0-211.50.1.el10_2, +4 more
    fixed: vendor fix RHSA-2026:61887
  • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6) kernel-rt 5.14.0-570.152.1.el9_6, kernel-rt-kvm 5.14.0-570.152.1.el9_6, kernel-rt-core 5.14.0-570.152.1.el9_6, kernel-rt-modules 5.14.0-570.152.1.el9_6, kernel-rt-debug-kvm 5.14.0-570.152.1.el9_6, kernel-rt-debug-core 5.14.0-570.152.1.el9_6, +6 more
    fixed: vendor fix RHSA-2026:91492
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.158.1.rt7.499.el8_10, kernel-rt-core 4.18.0-553.158.1.rt7.499.el8_10, kernel-rt-modules 4.18.0-553.158.1.rt7.499.el8_10, kernel-rt-debug-core 4.18.0-553.158.1.rt7.499.el8_10, kernel-rt-debug-modules 4.18.0-553.158.1.rt7.499.el8_10, kernel-rt-modules-extra 4.18.0-553.158.1.rt7.499.el8_10, +2 more
    fixed: vendor fix RHSA-2026:59737
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 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
yes
Technical impact
partial
Assessed
23 d ago

Exploit prediction

0.80% chance of exploitation in the next 30 days, higher than 56% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
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.