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TI-2026-38478 Aliases CVE-2026-53392GHSA-3gfh-mq5v-c264

NFSv4/flexfiles: reject zero filehandle version count

Priority LOW 39CWE-20Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 14 fixed, 2 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-476.

Summary

In the Linux kernel, the following vulnerability has been resolved: NFSv4/flexfiles: reject zero filehandle version count ff_layout_alloc_lseg() decodes the filehandle-version array count from the flexfiles layout body. The value is used as the count for kzalloc_objs(), and the current code only rejects NULL. A zero count yields ZERO_SIZE_PTR, which can be stored in dss_info->fh_versions even though later flexfiles paths assume that at least one filehandle version exists. Reject fh_count == 0 before the allocation, matching the existing zero version_count validation in the flexfiles GETDEVICEINFO parser. A QEMU/KASAN run with a malformed flexfiles layout hit: KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] RIP: 0010:ff_layout_encode_ff_layoutupdate.isra.0+0x15f/0x750 ff_layout_encode_layoutreturn+0x683/0x970 nfs4_xdr_enc_layoutreturn+0x278/0x3a0 Kernel panic - not syncing: Fatal exception The patched kernel rejects the malformed layout without KASAN/oops/panic, and a valid fh_count=1 regression still opens, reads, and unmounts cleanly.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00529 44th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.10.261, 5.15.212, 6.1.178 +5Red Hat: 4 advisoriesRed Hat: 14 fixed, 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux4.0 and later5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.38, 7.1.3, 7.2Patch availableCNA
  • Linux VendorLinux Affected 4.0 and later Fixed in 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.38, 7.1.3, 7.2 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*4.0 to before 5.10.261; 5.11 to before 5.15.212; 5.16 to before 6.1.178; 6.2 to before 6.6.145; 6.7 to before 6.12.96; 6.13 to before 6.18.38; 6.19 to before 7.1.3VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.0 to before 5.10.261; 5.11 to before 5.15.212; 5.16 to before 6.1.178; 6.2 to before 6.6.145; 6.7 to before 6.12.96; 6.13 to before 6.18.38; 6.19 to before 7.1.3 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.38, 7.1.3, 7.2

Red Hat 4 advisories

  • RHSA-2026:63129 Released 2026-09-04 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.44.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.44.1.el9_8, kernel-64k-devel-5.14.0-687.44.1.el9_8 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.44.1.el9_8, kernel-64k-5.14.0-687.44.1.el9_8, kernel-64k-core-5.14.0-687.44.1.el9_8 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.44.1.el9_8, libperf-5.14.0-687.44.1.el9_8
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.44.1.el9_8, kernel-rt-64k-5.14.0-687.44.1.el9_8, kernel-rt-64k-core-5.14.0-687.44.1.el9_8 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.44.1.el9_8, kernel-rt-core-5.14.0-687.44.1.el9_8, kernel-rt-debug-5.14.0-687.44.1.el9_8 +9
  • RHSA-2026:63014 Released 2026-09-03 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.159.1.el8_10, kernel-4.18.0-553.159.1.el8_10, kernel-abi-stablelists-4.18.0-553.159.1.el8_10 +19
    • Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.159.1.el8_10
  • RHSA-2026:63013 Released 2026-09-03 · Red Hat rating Important
    kernel-rt security, bug fix, and enhancement update
    • Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-core-4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-debug-4.18.0-553.159.1.rt7.500.el8_10 +9
    • Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-core-4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-debug-4.18.0-553.159.1.rt7.500.el8_10 +7
Show 1 more Red Hat advisories
  • RHSA-2026:61887 Released 2026-09-01 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.50.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.50.1.el10_2, kernel-64k-devel-6.12.0-211.50.1.el10_2 +12
    • 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-64k-core-6.12.0-211.50.1.el10_2 +29
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.50.1.el10_2, libperf-6.12.0-211.50.1.el10_2
    • 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-64k-core-6.12.0-211.50.1.el10_2 +21
    • 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-debug-6.12.0-211.50.1.el10_2 +9

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 7AffectedNo fix yet
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:61887
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:63129
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:61887
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2026:63014
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:63129
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2026:63014
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:61887
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:63129
Red Hat Enterprise Linux NFV (v. 8)Fixed RHSA-2026:63013
Red Hat Enterprise Linux RT (v. 8)Fixed RHSA-2026:63013
Red Hat Enterprise Linux Real Time (v. 10)Fixed RHSA-2026:61887
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2026:63129
Red Hat Enterprise Linux Real Time for NFV (v. 10)Fixed RHSA-2026:61887
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2026:63129
Not affected: 1 product
  • Red Hat Enterprise Linux 6

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-53392
  2. 2026-10-03 Alias added: GHSA-3gfh-mq5v-c264
  3. 2026-10-16 CISA SSVC decision points changed
  4. 2026-10-19 Weakness changed · CISA ADP
  5. 2026-11-06 CVSS score changed · Red Hat

References

Patch 8

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences