CVE-2025-68206: Linux kernel · netfilter: nft_ct: add seqadj extension for natted connections
Affects Linux kernelSource CVE Database V5
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
Thin evidence
One scorer or none| CNA (Linux) | CVSS 3.1 | 7.5 |
|---|
- 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:HExploitation evidence
Disclosed: evidence found.
CVE published 16 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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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
- git.kernel.org/stable/c/83273af0b60c093ba0085c205864d8542e1b1653 (opens in a new tab)
- git.kernel.org/stable/c/b19492c25eff04852e0cb58f9bb8238b6695ed2d (opens in a new tab)
- git.kernel.org/stable/c/4de80f0dc3868408dd7fe9817e507123c9dd8bb0 (opens in a new tab)
- git.kernel.org/stable/c/b477ef7fa612fa45b6b3134d90d1eeb09396500a (opens in a new tab)
- git.kernel.org/stable/c/4ab2cd906e4e1a19ddbda6eb532851b0e9cda110 (opens in a new tab)
- git.kernel.org/stable/c/2b52d89cbbb0dbe3e948d8d9a91e704316dccfe6 (opens in a new tab)
- git.kernel.org/stable/c/90918e3b6404c2a37837b8f11692471b4c512de2 (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-082556.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-019113.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-457936.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)