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NVD / CVE Program· CNA Linux

CVE-2026-53000: netfilter: nat: use kfree_rcu to release ops

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.18% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 050f98e56782b14677c5bae50800e60775bbf6bb, 32fdd2e38e7435a368d88f5977a7d6585ebc8b0e, 3c7511f38ab511b791196b13ae48bf4973bf7dfd; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 050f98e56782b14677c5bae50800e60775bbf6bb, 32fdd2e38e7435a368d88f5977a7d6585ebc8b0e, 3c7511f38ab511b791196b13ae48bf4973bf7dfd; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: netfilter: nat: use kfree_rcu to release ops Florian Westphal says: "Historically this is not an issue, even for normal base hooks: the data path doesn't use the original nf_hook_ops that are used to register the callbacks. However, in v5.14 I added the ability to dump the active netfilter hooks from userspace. This code will peek back into the nf_hook_ops that are available at the tail of the pointer-array blob used by the datapath. The nat hooks are special, because they are called indirectly from the central nat dispatcher hook. They are currently invisible to the nfnl hook dump subsystem though. But once that changes the nat ops structures have to be deferred too." Update nf_nat_register_fn() to deal with partial exposition of the hooks from error path which can be also an issue for nfnetlink_hook.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Jun 24, 2026
Updated
Oct 30, 2026
EPSS
0.1% · 7th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
7.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel
redhatenterprise linux

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel5.14 and later · before 6.18.33
  • linux linux kernel6.19 and later · before 7.0.10
  • redhat enterprise linux10.0
  • redhat enterprise linux9.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 5.14affected
    • e2cf17d3774c323ef6dab6e9f7c0cfc5e742afd9 and later · before bf17f1d3b307196d9282c4b1dd8be0d0e5f8e529affected · git
    • e2cf17d3774c323ef6dab6e9f7c0cfc5e742afd9 and later · before ede973d62d26d9c550269af05366ab9e30fc92eeaffected · git
    • e2cf17d3774c323ef6dab6e9f7c0cfc5e742afd9 and later · before 050f98e56782b14677c5bae50800e60775bbf6bbaffected · git
    • e2cf17d3774c323ef6dab6e9f7c0cfc5e742afd9 and later · before 32fdd2e38e7435a368d88f5977a7d6585ebc8b0eaffected · git
    • e2cf17d3774c323ef6dab6e9f7c0cfc5e742afd9 and later · before 3c7511f38ab511b791196b13ae48bf4973bf7dfdaffected · git
    • e2cf17d3774c323ef6dab6e9f7c0cfc5e742afd9 and later · before 6eda0d771f94267f73f57c94630aa47e90957915affected · git
    • before 5.14not affected · semver
    • 6.1.191 and later · up to and including 6.1.*not affected · semver
    • 6.6.160 and later · up to and including 6.6.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:9kernelbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64kbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-corebefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-debugbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-debug-corebefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-debug-develbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-debug-devel-matchedbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-debug-modulesbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-debug-modules-corebefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-debug-modules-extrabefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-develbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-devel-matchedbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-modulesbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-modules-corebefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-modules-extrabefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-abi-stablelistsbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-corebefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-cross-headersbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-debugbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-debug-corebefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-debug-develbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-debug-devel-matchedbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-debug-modulesbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-debug-modules-corebefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-52998Jun 24, 2026 · netfilter: nfnetlink_osf: fix potential NULL dereference in ttl check
    30Monitor
  • ← EarlierCVE-2026-52999Jun 24, 2026 · netfilter: nfnetlink_osf: fix out-of-bounds read on option matching
    36Monitor
  • Later →CVE-2026-53001Jun 24, 2026 · netfilter: xtables: restrict several matches to inet family
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux050f98e56782b14677c5bae50800e60775bbf6bbVendor (CNA)
Linux Linux32fdd2e38e7435a368d88f5977a7d6585ebc8b0eVendor (CNA)
Linux Linux3c7511f38ab511b791196b13ae48bf4973bf7dfdVendor (CNA)
Linux Linux6eda0d771f94267f73f57c94630aa47e90957915Vendor (CNA)
Linux Linuxbf17f1d3b307196d9282c4b1dd8be0d0e5f8e529Vendor (CNA)
Linux Linuxede973d62d26d9c550269af05366ab9e30fc92eeVendor (CNA)
azl3 kernel 6.6.150.1-1 on Azure Linux 3.0—Microsoft (MSRC)
azl3 kernel 6.6.152.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
almalinux:kernel5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-core5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-core5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-core5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel-matched5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
debian:linux6.12.115-2 · Debian:13Package registry (OSV)
debian:linux7.0.10-1 · Debian:14Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:6.12.0-55.98.1.el10_0 · Red Hat:enterprise_linux_eus:10.0Package registry (OSV)
red hat:kernel-64k-debug-devel0:6.12.0-55.98.1.el10_0 · Red Hat:enterprise_linux_eus:10.0Package registry (OSV)
red hat:kernel-64k-debug-devel-matched0:6.12.0-55.98.1.el10_0 · Red Hat:enterprise_linux_eus:10.0Package registry (OSV)
red hat:kernel-64k-debuginfo0:6.12.0-55.98.1.el10_0 · Red Hat:enterprise_linux_eus:10.0Package registry (OSV)
red hat:kernel-64k-devel0:6.12.0-55.98.1.el10_0 · Red Hat:enterprise_linux_eus:10.0Package registry (OSV)
red hat:kernel-64k-devel-matched0:6.12.0-55.98.1.el10_0 · Red Hat:enterprise_linux_eus:10.0Package registry (OSV)
red hat:kernel-debug-debuginfo0:6.12.0-55.98.1.el10_0 · Red Hat:enterprise_linux_eus:10.0Package registry (OSV)

+6

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-6380925 days apartbpf: use kvfree() for replaced sysctl write buffer
    31Monitor
  • CVE-2026-6398625 days apartethtool: tsinfo: don't pass ERR_PTR to genlmsg_cancel on prepare failure
    22Monitor
  • CVE-2026-9816093 days apartstaging: rtl8723bs: fix mismatched free of HalData in rtw_sdio_if1_init()
    22Monitor
  • CVE-2022-49160483 days apartscsi: qla2xxx: Fix crash during module load unload test
    22Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-763 · Release of Invalid Pointer or Reference

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (12 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records