CVE-2025-71146Network attack vectorHinoki check available

Connection denial via leaked conntrack references

Published Jan 23, 2026 · Updated Jan 23, 2026

Resource leakage in Linux Kernel netfilter allows remote attackers to interrupt new connections via crafted packet flows. The __nf_conncount_add and insert_tree paths return without releasing a refcounted conntrack object obtained from the packet. A reachable host must process traffic through a raw-table connlimit rule before conntrack attachment; repeated flows can exhaust per-namespace conntrack counts or stall namespace cleanup.

CVSS severity7.5
High
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Resource leakage in Linux Kernel netfilter allows remote attackers to interrupt new connections via crafted packet flows. The __nf_conncount_add and insert_tree paths return without releasing a refcounted conntrack object obtained from the packet. A reachable host must process traffic through a raw-table connlimit rule before conntrack attachment; repeated flows can exhaust per-namespace conntrack counts or stall namespace cleanup.

The record

CVE
CVE-2025-71146
Published
Jan 23, 2026
Updated
Jan 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-401, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 23, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3558faee8aace3541189c3a2ca45c7e85e144b44 <0b88be7211d21a0d68bb1e56dc805944e3654d6f
  2. Affected versionversion=6.19-rc1
  3. Affected versionversion=6e86f0eca857ee42787e30e9ec0b726aebfcae0a <08fa37f4c8c59c294e9c18fea2d083ee94074e5a
  4. Affected versionversion=8c2da7330214ce30f8333d1799a27ed0a9418f07
  5. Affected versionversion=8d5a2c94c24dcc226863a7c2b5034750370c2189 <f381a33f34dda9e4023e38ba68c943bca83245e9
  6. Affected versionversion=b160895d6bc9690459b16ef87799c9bd456af3ec <e1ac8dce3a893641bef224ad057932f142b8a36f
  7. Affected versionversion=be102eb6a0e7c03db00e50540622f4e43b2d2844 <2e2a720766886190a6d35c116794693aabd332b6
  8. Affected versionversion=da9f247fb5efcd5a2730cdc989291b383c439e10 <325eb61bb30790ea27782203a17b007ce1754a67
  9. Affected versionversion=f6904ed15ed1a188543057e3cb0d02daa80edfc9 <4bd2b89f4028f250dd1c1625eb3da1979b04a5e8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=3558faee8aace3541189c3a2ca45c7e85e144b44 <0b88be7211d21a0d68bb1e56dc805944e3654d6f; version=6.19-rc1; version=6e86f0eca857ee42787e30e9ec0b726aebfcae0a <08fa37f4c8c59c294e9c18fea2d083ee94074e5a; version=8c2da7330214ce30f8333d1799a27ed0a9418f07; version=8d5a2c94c24dcc226863a7c2b5034750370c2189 <f381a33f34dda9e4023e38ba68c943bca83245e9; version=b160895d6bc9690459b16ef87799c9bd456af3ec <e1ac8dce3a893641bef224ad057932f142b8a36f; version=be102eb6a0e7c03db00e50540622f4e43b2d2844 <2e2a720766886190a6d35c116794693aabd332b6; version=da9f247fb5efcd5a2730cdc989291b383c439e10 <325eb61bb30790ea27782203a17b007ce1754a67; version=f6904ed15ed1a188543057e3cb0d02daa80edfc9 <4bd2b89f4028f250dd1c1625eb3da1979b04a5e8

Published CVSS scores

5.7SUSECVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
4.7SUSECVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
7.5kernel.orgCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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