CVE-2025-39968

Host networking denial via unbounded VF filters

Published Oct 15, 2025 · Updated Oct 15, 2025

Resource exhaustion in the Linux i40e driver allows local users controlling an assigned VF to interrupt host networking. i40e_vc_add_cloud_filter accepts repeated VIRTCHNL_OP_ADD_CLOUD_FILTER messages, allocates a cloud-filter object for each, and never enforces a maximum. An assigned VF with ADq enabled and spoof checking disabled can exhaust host memory, monopolize the PF work queue and filter table, and take networking down for the host and peer guests.

CVSS severity7.3
High
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in the Linux i40e driver allows local users controlling an assigned VF to interrupt host networking. i40e_vc_add_cloud_filter accepts repeated VIRTCHNL_OP_ADD_CLOUD_FILTER messages, allocates a cloud-filter object for each, and never enforces a maximum. An assigned VF with ADq enabled and spoof checking disabled can exhaust host memory, monopolize the PF work queue and filter table, and take networking down for the host and peer guests.

The record

CVE
CVE-2025-39968
Published
Oct 15, 2025
Updated
Oct 15, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 15, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 15, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.17
  2. Affected versionversion=e284fc280473bed23f2e1ed324e102a48f7d17e1 <02aae5fcdd34c3a55a243d80a1b328a35852a35c
  3. Affected versionversion=e284fc280473bed23f2e1ed324e102a48f7d17e1 <77a35be582dff4c80442ebcdce24d45eed8a6ce4
  4. Affected versionversion=e284fc280473bed23f2e1ed324e102a48f7d17e1 <8b13df5aa877b9e4541e301a58a84c42d84d2d9a
  5. Affected versionversion=e284fc280473bed23f2e1ed324e102a48f7d17e1 <9176e18681cb0d34c5acc87bda224f5652af2ab8
  6. Affected versionversion=e284fc280473bed23f2e1ed324e102a48f7d17e1 <cb79fa7118c150c3c76a327894bb2eb878c02619
  7. Affected versionversion=e284fc280473bed23f2e1ed324e102a48f7d17e1 <d33e5d6631ac4fddda235a7815babc9d3f124299
  8. Affected versionversion=e284fc280473bed23f2e1ed324e102a48f7d17e1 <e490d8c5a54e0dd1ab22417d72c3a7319cf0f030
  9. Affected versionversion=e284fc280473bed23f2e1ed324e102a48f7d17e1 <edecce7abd7152b48e279b4fa0a883d1839bb577

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.17; version=e284fc280473bed23f2e1ed324e102a48f7d17e1 <02aae5fcdd34c3a55a243d80a1b328a35852a35c; version=e284fc280473bed23f2e1ed324e102a48f7d17e1 <77a35be582dff4c80442ebcdce24d45eed8a6ce4; version=e284fc280473bed23f2e1ed324e102a48f7d17e1 <8b13df5aa877b9e4541e301a58a84c42d84d2d9a; version=e284fc280473bed23f2e1ed324e102a48f7d17e1 <9176e18681cb0d34c5acc87bda224f5652af2ab8; version=e284fc280473bed23f2e1ed324e102a48f7d17e1 <cb79fa7118c150c3c76a327894bb2eb878c02619; version=e284fc280473bed23f2e1ed324e102a48f7d17e1 <d33e5d6631ac4fddda235a7815babc9d3f124299; version=e284fc280473bed23f2e1ed324e102a48f7d17e1 <e490d8c5a54e0dd1ab22417d72c3a7319cf0f030; version=e284fc280473bed23f2e1ed324e102a48f7d17e1 <edecce7abd7152b48e279b4fa0a883d1839bb577

Published CVSS scores

7.3LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:L/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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

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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