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VulnerabilityPublished Updated

CVE-2025-71146: Linux kernel · netfilter: nf_conncount: fix leaked ct in error paths

Affects Linux kernelSource GCVE Database

0

Not known to be exploited · CVSS 7.5 High · fixed in 6.17.0-1012.12~24.04.1 : patch Linux kernel soon.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score
7.5High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.2% chance of exploitation in 30 days – higher than 20% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 6.17.0-1012.12~24.04.1, 6.17.0-1013.13~24.04.1, 6.17.0-22.22~24.04.1 +10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 23 Jan 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threatsAffected
  • <6.17.0-22.22
Fixed in
  • 6.17.0-22.22
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1012.12
Fixed in
  • 6.17.0-1012.12
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1013.13
Fixed in
  • 6.17.0-1013.13
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1012.12
Fixed in
  • 6.17.0-1012.12
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1011.11
Fixed in
  • 6.17.0-1011.11
Ubuntu 25.10linux-raspipkg:deb/ubuntu/linux-raspi?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1013.13
Fixed in
  • 6.17.0-1013.13

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A patch is available and included in Linux kernel versions 6.17.0-22.22 and later. Users should update their Linux kernel to the fixed versions provided by their vendor, such as those listed in the Ubuntu advisories USN-8177-1 and USN-8177-2, and reboot the system to apply the fixes. Due to an ABI change, recompilation and reinstallation of third-party kernel modules may be required. Follow vendor instructions for updating and rebooting. No additional mitigation is required beyond applying the official patch.

Description

CVE-2025-71146 is a vulnerability in the Linux kernel's netfilter nf_conncount component where connection tracking (ct) objects may be leaked due to error paths skipping reference count checks. This flaw was fixed by ensuring the reference count check is always performed. The vulnerability has a CVSS 3.1 score of 7.5 (medium severity) with an impact on availability (denial of service). A patch is available and included in Linux kernel versions 6.17.0-22.22 and later. The vendor advisory from Ubuntu confirms the fix and recommends updating to patched kernel versions and rebooting the system. No known exploits are reported in the wild.

References

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