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NVD / CVE Program· CNA Linux

CVE-2025-37997: netfilter: ipset: fix region locking in hash types

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: 0.18% (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 00cfc5fad1491796942a948808afb968a0a3f35b, 226ce0ec38316d9e3739e73a64b6b8304646c658, 5.4.294; azl3 kernel 6.6.85.1-4 on Azure Linux 3.0 6.6.92.2-1; azl3 kernel 6.6.92.2-1 on Azure Linux 3.0 6.6.92.2-1.
  • Severity is disputed: the assigning authority (CNA) scores it 7.8, NVD 5.5.

Low priority for now. Upgrade to Linux Linux 00cfc5fad1491796942a948808afb968a0a3f35b, 226ce0ec38316d9e3739e73a64b6b8304646c658, 5.4.294; azl3 kernel 6.6.85.1-4 on Azure Linux 3.0 6.6.92.2-1; azl3 kernel 6.6.92.2-1 on Azure Linux 3.0 6.6.92.2-1 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: ipset: fix region locking in hash types Region locking introduced in v5.6-rc4 contained three macros to handle the region locks: ahash_bucket_start(), ahash_bucket_end() which gave back the start and end hash bucket values belonging to a given region lock and ahash_region() which should give back the region lock belonging to a given hash bucket. The latter was incorrect which can lead to a race condition between the garbage collector and adding new elements when a hash type of set is defined with timeouts.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
May 29, 2025
Updated
Oct 15, 2026
EPSS
0.1% · 7th percentile

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 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
5.5
CNA · Linux
7.8
2.3 point gap

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

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.

Follow CVE-2025-37997

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • 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
debiandebian linux

Affected versions

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

  • debian debian linux11.0
  • linux linux kernel5.5.8 and later · before 5.6
  • linux linux kernel5.6.1 and later · before 5.10.238
  • linux linux kernel5.11 and later · before 5.15.183
  • linux linux kernel5.16 and later · before 6.1.139
  • linux linux kernel5.4.24 and later · before 5.4.294
  • linux linux kernel6.7 and later · before 6.12.29
  • linux linux kernel6.13 and later · before 6.14.7
  • linux linux kernel6.2 and later · before 6.6.91
  • linux linux kernel5.6
  • linux linux kernel6.15

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

    • a469bab3386aebff33c59506f3a95e35b91118fd, 5.6affected
    • 5dd9488ae41070b69d2f4acb580f77db5705f9ca and later · before 00cfc5fad1491796942a948808afb968a0a3f35baffected · git
    • f66ee0410b1c3481ee75e5db9b34547b4d582465 and later · before 226ce0ec38316d9e3739e73a64b6b8304646c658affected · git
    • f66ee0410b1c3481ee75e5db9b34547b4d582465 and later · before 82c1eb32693bc48251d92532975e19160987e5b9affected · git
    • f66ee0410b1c3481ee75e5db9b34547b4d582465 and later · before aa77294b0f73bb8265987591460cd25b8722c3dfaffected · git
    • f66ee0410b1c3481ee75e5db9b34547b4d582465 and later · before a3dfec485401943e315c394c29afe2db8f9481d6affected · git
    • f66ee0410b1c3481ee75e5db9b34547b4d582465 and later · before e2ab67672b2288521a6146034a971f9a82ffc5c5affected · git
    • f66ee0410b1c3481ee75e5db9b34547b4d582465 and later · before 6e002ecc1c8cfdfc866b9104ab7888da54613e59affected · git
    • f66ee0410b1c3481ee75e5db9b34547b4d582465 and later · before 8478a729c0462273188263136880480729e9efcaaffected · git
    • 5.4.24 and later · before 5.4.294affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.139-16.1.139-1
Debian:13linuxbefore 6.12.29-16.12.29-1

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-2025-37996May 29, 2025 · KVM: arm64: Fix uninitialized memcache pointer in user_mem_abort()
    22Monitor
  • ← EarlierCVE-2025-37999May 29, 2025 · fs/erofs/fileio: call erofs_onlinefolio_split() after bio_add_folio()
    22Monitor
  • Later →CVE-2025-37998May 29, 2025 · openvswitch: Fix unsafe attribute parsing in output_userspace()
    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 Linux00cfc5fad1491796942a948808afb968a0a3f35bVendor (CNA)
Linux Linux226ce0ec38316d9e3739e73a64b6b8304646c658Vendor (CNA)
Linux Linux5.4.294Vendor (CNA)
Linux Linux5.6Vendor (CNA)
Linux Linux6e002ecc1c8cfdfc866b9104ab7888da54613e59Vendor (CNA)
Linux Linux82c1eb32693bc48251d92532975e19160987e5b9Vendor (CNA)
Linux Linux8478a729c0462273188263136880480729e9efcaVendor (CNA)
Linux Linuxa3dfec485401943e315c394c29afe2db8f9481d6Vendor (CNA)
Linux Linuxaa77294b0f73bb8265987591460cd25b8722c3dfVendor (CNA)
Linux Linuxe2ab67672b2288521a6146034a971f9a82ffc5c5Vendor (CNA)
azl3 kernel 6.6.85.1-4 on Azure Linux 3.06.6.92.2-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 kernel 6.6.92.2-1 on Azure Linux 3.06.6.92.2-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.139-1 · Debian:12Package registry (OSV)

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)

CWE-667 · Improper Locking

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.

Change log

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

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

References

Show all references (9 more)

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

All records