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VulnerabilityPublished Updated

CVE-2025-68206: Linux kernel · netfilter: nft_ct: add seqadj extension for natted connections

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · CVSS 7.5 High · fixed in b19492c25eff04852e0cb58f9bb8238b6695ed2d : patch Linux kernel soon.

Data as of 10 Nov 2026, 13:17 UTC

CVSS 3.1 base score
7.5High
How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none
CVSS scores by source
CNA (Linux)CVSS 3.17.5
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers can reliably automate steps 1–4 of the kill chain
Technical impact
Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-10-15.

Patch
Available – fixed in b19492c25eff04852e0cb58f9bb8238b6695ed2d, b477ef7fa612fa45b6b3134d90d1eeb09396500a, 90918e3b6404c2a37837b8f11692471b4c512de2 +4
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 16 Dec 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: 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 10 Nov 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 1a64edf54f55d7956cf5a0d95898bc1f84f9b818, < b19492c25eff04852e0cb58f9bb8238b6695ed2d
Fixed in
  • b19492c25eff04852e0cb58f9bb8238b6695ed2d
LinuxLinuxAffected
  • ≥ 1a64edf54f55d7956cf5a0d95898bc1f84f9b818, < b477ef7fa612fa45b6b3134d90d1eeb09396500a
Fixed in
  • b477ef7fa612fa45b6b3134d90d1eeb09396500a
LinuxLinuxAffected
  • ≥ 1a64edf54f55d7956cf5a0d95898bc1f84f9b818, < 90918e3b6404c2a37837b8f11692471b4c512de2
Fixed in
  • 90918e3b6404c2a37837b8f11692471b4c512de2
LinuxLinuxAffected
  • ≥ 1a64edf54f55d7956cf5a0d95898bc1f84f9b818, < 83273af0b60c093ba0085c205864d8542e1b1653
Fixed in
  • 83273af0b60c093ba0085c205864d8542e1b1653
LinuxLinuxAffected
  • ≥ 1a64edf54f55d7956cf5a0d95898bc1f84f9b818, < 4de80f0dc3868408dd7fe9817e507123c9dd8bb0
Fixed in
  • 4de80f0dc3868408dd7fe9817e507123c9dd8bb0
LinuxLinuxAffected
  • ≥ 1a64edf54f55d7956cf5a0d95898bc1f84f9b818, < 4ab2cd906e4e1a19ddbda6eb532851b0e9cda110
Fixed in
  • 4ab2cd906e4e1a19ddbda6eb532851b0e9cda110

AI-suggested

A fix is available and has been applied in the Linux kernel versions identified by the fixed commit hashes. Users should update to a Linux kernel version that includes these fixes to resolve the issue. No additional mitigation steps are indicated or required beyond applying the official patch.

Description

CVE-2025-68206 addresses a vulnerability in the Linux kernel's netfilter nft_ct module related to sequence adjustment for NATed FTP connections. The issue affects FTP traffic using PASV/EPSV modes, where packet payload rewriting requires adjustments to TCP sequence and acknowledgment numbers. Without the fix, FTP NAT changes may fail, causing connection closures and kernel warnings. The vulnerability has been resolved by adding the required sequence adjustment extension when a conntrack helper is assigned to a connection with NAT bindings.

References

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