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VulnerabilityPublished Updated

CVE-2025-39973: Linux kernel · i40e: add validation for ring_len param

Affects Linux kernelSource GCVE Database

0

Not known to be exploited · CVSS 8.8 High · fixed in 5.15.0-1100.107~20.04.2 : patch Linux kernel soon.

Data as of 28 Oct 2026, 11:20 UTC

CVSS 3.1 base score
8.8High
How severe the flaw is on the 0–10 CVSS scale.
Patch
Available – fixed in 5.15.0-1100.107~20.04.2, 5.15.0-1110.119~20.04.1, 5.15.0-1100.109~20.04.1 +68
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 15 Oct 2025

  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
  • <6.17.0-6.6
Fixed in
  • 6.17.0-6.6
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1003.3
Fixed in
  • 6.17.0-1003.3
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1006.6
Fixed in
  • 6.17.0-1006.6
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threatsAffected
  • 6.17.0-1003.3 – 6.17.0-1017.17
10 affected builds
Fixed in–
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1003.3
Fixed in
  • 6.17.0-1003.3
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1003.3
Fixed in
  • 6.17.0-1003.3

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 multiple updated Linux kernel versions (notably in the 5.15.x series). Users should update their Linux kernel to one of the fixed versions listed (e.g., 5.15.0-1094.97~20.04.1 or later) to remediate this vulnerability. After updating, a system reboot is required. No additional mitigations are indicated by the vendor advisory.

Description

CVE-2025-39973 is a vulnerability in the Linux kernel's i40e network driver where the ring_len parameter provided by a virtual function (VF) was assigned directly to hardware memory context without validation. This allowed potentially invalid queue lengths to be set, bypassing hardware constraints. The issue was fixed by adding upper boundary checks and alignment requirements for Tx and Rx queue lengths. The vulnerability affects multiple Linux kernel versions prior to fixed releases in the 5.15.x series and some older 3.x versions. It has a high severity score and requires updating to patched kernel versions.

References

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