CVE-2025-39968: Linux kernel · i40e: add max boundary check for VF filters
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.3 High · fixed in 5.15.0-1100.107~20.04.2 : patch Linux kernel soon.
Data as of 28 Oct 2026, 11:21 UTC
- 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:N/I:L/A:HExploitation evidence
Disclosed: evidence found.
CVE published 15 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-8033-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8034-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8034-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-6 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-7 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-8 (opens in a new tab)
- ubuntu.com/security/notices/USN-8095-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8100-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=questingOther threats | Affected
| Fixed in
|
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 fixed Linux kernel versions as listed in the vendor advisory. Users should update to these fixed kernel versions and reboot their systems to apply the changes. The vendor advisory from Ubuntu (USN-8033-1) provides detailed update instructions. No additional mitigation steps are required beyond applying the official fixes.
Description
A vulnerability in the Linux kernel's i40e driver was fixed by adding a maximum boundary check for Virtual Function (VF) filters. Previously, there was no limit on the number of filters a VF could request, which could lead to denial of service or other impacts. This issue affects multiple Linux kernel versions prior to the fixed releases. The vulnerability has a CVSS score of 7.3 (high severity).
References
- ubuntu.com/security/CVE-2025-39968 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-39968 (opens in a new tab)
- git.kernel.org/linus/cb79fa7118c150c3c76a327894bb2eb878c02619 (opens in a new tab)
- git.kernel.org/stable/c/02aae5fcdd34c3a55a243d80a1b328a35852a35c (opens in a new tab)
- git.kernel.org/stable/c/77a35be582dff4c80442ebcdce24d45eed8a6ce4 (opens in a new tab)
- git.kernel.org/stable/c/8b13df5aa877b9e4541e301a58a84c42d84d2d9a (opens in a new tab)
- git.kernel.org/stable/c/9176e18681cb0d34c5acc87bda224f5652af2ab8 (opens in a new tab)
- git.kernel.org/stable/c/cb79fa7118c150c3c76a327894bb2eb878c02619 (opens in a new tab)
- git.kernel.org/stable/c/d33e5d6631ac4fddda235a7815babc9d3f124299 (opens in a new tab)
- git.kernel.org/stable/c/e490d8c5a54e0dd1ab22417d72c3a7319cf0f030 (opens in a new tab)
- git.kernel.org/stable/c/edecce7abd7152b48e279b4fa0a883d1839bb577 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8034-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8034-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-6 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-7 (opens in a new tab)