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NVD / CVE Program· CNA Linux

CVE-2025-21648: netfilter: conntrack: clamp maximum hashtable size to INT_MAX

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.21% (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 5552b4fd44be3393b930434a7845d8d95a2a3c33, a965f7f0ea3ae61b9165bed619d5d6da02c75f80, b1b2353d768f1b80cd7fe045a70adee576b9b338.

Low priority for now. Upgrade to Linux Linux 5552b4fd44be3393b930434a7845d8d95a2a3c33, a965f7f0ea3ae61b9165bed619d5d6da02c75f80, b1b2353d768f1b80cd7fe045a70adee576b9b338 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: conntrack: clamp maximum hashtable size to INT_MAX Use INT_MAX as maximum size for the conntrack hashtable. Otherwise, it is possible to hit WARN_ON_ONCE in __kvmalloc_node_noprof() when resizing hashtable because __GFP_NOWARN is unset. See: 0708a0afe291 ("mm: Consider __GFP_NOWARN flag for oversized kvmalloc() calls") Note: hashtable resize is only possible from init_netns.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Jan 19, 2025
Updated
Oct 15, 2026
EPSS
0.2% · 12th percentile
CWE
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

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

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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

Affected versions

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

  • linux linux kernel5.16 and later · before 6.1.125
  • linux linux kernel4.7.1 and later · before 5.10.234
  • linux linux kernel5.11 and later · before 5.15.177
  • linux linux kernel6.2 and later · before 6.6.72
  • linux linux kernel6.7 and later · before 6.12.10
  • linux linux kernel4.7
  • linux linux kernel6.13

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

    • 4.7affected
    • 9cc1c73ad66610bffc80b691136ffc1e9a3b1a58 and later · before a965f7f0ea3ae61b9165bed619d5d6da02c75f80affected · git
    • 9cc1c73ad66610bffc80b691136ffc1e9a3b1a58 and later · before b1b2353d768f1b80cd7fe045a70adee576b9b338affected · git
    • 9cc1c73ad66610bffc80b691136ffc1e9a3b1a58 and later · before 5552b4fd44be3393b930434a7845d8d95a2a3c33affected · git
    • 9cc1c73ad66610bffc80b691136ffc1e9a3b1a58 and later · before d5807dd1328bbc86e059c5de80d1bbee9d58ca3daffected · git
    • 9cc1c73ad66610bffc80b691136ffc1e9a3b1a58 and later · before f559357d035877b9d0dcd273e0ff83e18e1d46aaaffected · git
    • 9cc1c73ad66610bffc80b691136ffc1e9a3b1a58 and later · before b541ba7d1f5a5b7b3e2e22dc9e40e18a7d6dbc13affected · git
    • before 4.7not affected · semver
    • 5.10.234 and later · up to and including 5.10.*not affected · semver
    • 5.15.177 and later · up to and including 5.15.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.128-16.1.128-1
Debian:13linuxbefore 6.12.10-16.12.10-1
openSUSE:Leap 15.6dtb-aarch64before 6.4.0-150600.23.53.16.4.0-150600.23.53.1
openSUSE:Leap 15.6kernel-64kbbefore 6.4.0-150600.23.53.16.4.0-150600.23.53.1
openSUSE:Leap 15.6kernel-azurebefore 6.4.0-150600.8.40.16.4.0-150600.8.40.1
openSUSE:Leap 15.6kernel-debugbefore 6.4.0-150600.23.53.16.4.0-150600.23.53.1
openSUSE:Leap 15.6kernel-defaultbefore 6.4.0-150600.23.53.16.4.0-150600.23.53.1
openSUSE:Leap 15.6kernel-default-basebefore 6.4.0-150600.23.53.1.150600.12.24.16.4.0-150600.23.53.1.150600.12.24.1
openSUSE:Leap 15.6kernel-docsbefore 6.4.0-150600.23.53.16.4.0-150600.23.53.1
openSUSE:Leap 15.6kernel-kvmsmallbefore 6.4.0-150600.23.53.16.4.0-150600.23.53.1
openSUSE:Leap 15.6kernel-obs-buildbefore 6.4.0-150600.23.53.16.4.0-150600.23.53.1
openSUSE:Leap 15.6kernel-obs-qabefore 6.4.0-150600.23.53.16.4.0-150600.23.53.1
openSUSE:Leap 15.6kernel-sourcebefore 6.4.0-150600.23.53.16.4.0-150600.23.53.1
openSUSE:Leap 15.6kernel-source-azurebefore 6.4.0-150600.8.40.16.4.0-150600.8.40.1
openSUSE:Leap 15.6kernel-symsbefore 6.4.0-150600.23.53.16.4.0-150600.23.53.1
openSUSE:Leap 15.6kernel-syms-azurebefore 6.4.0-150600.8.40.16.4.0-150600.8.40.1
openSUSE:Leap 15.6kernel-zfcpdumpbefore 6.4.0-150600.23.53.16.4.0-150600.23.53.1
Red Hat:rhel_eus:9.6::appstreamkernel-64k-debug-debuginfobefore 0:5.14.0-570.125.1.el9_60:5.14.0-570.125.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-64k-debug-develbefore 0:5.14.0-570.125.1.el9_60:5.14.0-570.125.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-64k-debug-devel-matchedbefore 0:5.14.0-570.125.1.el9_60:5.14.0-570.125.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-64k-debuginfobefore 0:5.14.0-570.125.1.el9_60:5.14.0-570.125.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-64k-develbefore 0:5.14.0-570.125.1.el9_60:5.14.0-570.125.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-64k-devel-matchedbefore 0:5.14.0-570.125.1.el9_60:5.14.0-570.125.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-debug-debuginfobefore 0:5.14.0-570.125.1.el9_60:5.14.0-570.125.1.el9_6

+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-2025-21640Jan 19, 2025 · sctp: sysctl: cookie_hmac_alg: avoid using current->nsproxy
    22Monitor
  • ← EarlierCVE-2025-21645Jan 19, 2025 · platform/x86/amd/pmc: Only disable IRQ1 wakeup where i8042 actually enabled it
    22Monitor
  • Later →CVE-2025-21650Jan 19, 2025 · net: hns3: fixed hclge_fetch_pf_reg accesses bar space out of bounds issue
    31Monitor

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 Linux5552b4fd44be3393b930434a7845d8d95a2a3c33Vendor (CNA)
Linux Linuxa965f7f0ea3ae61b9165bed619d5d6da02c75f80Vendor (CNA)
Linux Linuxb1b2353d768f1b80cd7fe045a70adee576b9b338Vendor (CNA)
Linux Linuxb541ba7d1f5a5b7b3e2e22dc9e40e18a7d6dbc13Vendor (CNA)
Linux Linuxd5807dd1328bbc86e059c5de80d1bbee9d58ca3dVendor (CNA)
Linux Linuxf559357d035877b9d0dcd273e0ff83e18e1d46aaVendor (CNA)
debian:linux6.1.128-1 · Debian:12Package registry (OSV)
opensuse:dtb-aarch646.4.0-150600.23.53.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-64kb6.4.0-150600.23.53.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-azure6.4.0-150600.8.40.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-debug6.4.0-150600.23.53.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-default6.4.0-150600.23.53.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-default-base6.4.0-150600.23.53.1.150600.12.24.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-docs6.4.0-150600.23.53.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-kvmsmall6.4.0-150600.23.53.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-obs-build6.4.0-150600.23.53.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-obs-qa6.4.0-150600.23.53.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-source-azure6.4.0-150600.8.40.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-syms-azure6.4.0-150600.8.40.1 · openSUSE:Leap 15.6Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:5.14.0-570.125.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel0:5.14.0-570.125.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel-matched0:5.14.0-570.125.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-64k-debuginfo0:5.14.0-570.125.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-64k-devel0:5.14.0-570.125.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-64k-devel-matched0:5.14.0-570.125.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-debug-debuginfo0:5.14.0-570.125.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-debug-devel0:5.14.0-570.125.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-debug-devel-matched0:5.14.0-570.125.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-debuginfo0:5.14.0-570.125.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-debuginfo-common-aarch640:5.14.0-570.125.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)

+13

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.

No nightly-computed relations.

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).

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

Weakness class (CWE)

—

CVSS vector

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

nvd-primary

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. Fix✗ → ✓

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

References

Show all references (10 more)

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

All records