CVE-2025-68206Network attack vector

FTP service interruption via missing sequence adjustment

Published Dec 16, 2025 · Updated Dec 16, 2025

Improper sequence adjustment in Linux kernel netfilter allows remote attackers to interrupt FTP NAT sessions through PASV or EPSV traffic. When an FTP helper is assigned after DNAT, nft_ct fails to add the seqadj extension needed after payload rewrites change TCP length and sequence values. A remote FTP client can then break affected sessions; systems configured to panic on kernel warnings can instead suffer a complete kernel panic.

CVSS severity7.5
High
EPSS probability0.69%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper sequence adjustment in Linux kernel netfilter allows remote attackers to interrupt FTP NAT sessions through PASV or EPSV traffic. When an FTP helper is assigned after DNAT, nft_ct fails to add the seqadj extension needed after payload rewrites change TCP length and sequence values. A remote FTP client can then break affected sessions; systems configured to panic on kernel warnings can instead suffer a complete kernel panic.

The record

CVE
CVE-2025-68206
Published
Dec 16, 2025
Updated
Dec 16, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-166, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 16, 2025Record 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=1a64edf54f55d7956cf5a0d95898bc1f84f9b818 <2b52d89cbbb0dbe3e948d8d9a91e704316dccfe6
  2. Affected versionversion=1a64edf54f55d7956cf5a0d95898bc1f84f9b818 <90918e3b6404c2a37837b8f11692471b4c512de2
  3. Affected versionversion=4.12

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1a64edf54f55d7956cf5a0d95898bc1f84f9b818 <2b52d89cbbb0dbe3e948d8d9a91e704316dccfe6; version=1a64edf54f55d7956cf5a0d95898bc1f84f9b818 <90918e3b6404c2a37837b8f11692471b4c512de2; version=4.12

Published CVSS scores

6.8SUSECVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
5.5Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.5Linux Kernel CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.5SUSECVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-166Improper Handling of Missing Special Element
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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