CVE-2025-39945

Local privilege escalation via cnic teardown race

Published Oct 4, 2025 · Updated Oct 4, 2025

Use-after-free in the Linux kernel cnic driver allows local users to disclose or corrupt kernel memory during interface teardown. cnic_cm_stop_bnx2x_hw() cancels cyclic delete_task work asynchronously, so cnic_free_dev() frees cnic_dev while cnic_delete_task() can requeue and dereference it. Reaching the race requires local control of delegated bnx2x network and iSCSI or FCoE operations; successful exploitation grants kernel-level control, while failure can crash the host.

CVSS severity7.8
High
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux kernel cnic driver allows local users to disclose or corrupt kernel memory during interface teardown. cnic_cm_stop_bnx2x_hw() cancels cyclic delete_task work asynchronously, so cnic_free_dev() frees cnic_dev while cnic_delete_task() can requeue and dereference it. Reaching the race requires local control of delegated bnx2x network and iSCSI or FCoE operations; successful exploitation grants kernel-level control, while failure can crash the host.

The record

CVE
CVE-2025-39945
Published
Oct 4, 2025
Updated
Oct 4, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 4, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 4, 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=2.6.37
  2. Affected versionversion=fdf24086f4752aee5dfb40143c736250df017820 <0405055930264ea8fd26f4131466fa7652e5e47d
  3. Affected versionversion=fdf24086f4752aee5dfb40143c736250df017820 <0627e1481676669cae2df0d85b5ff13e7d24c390
  4. Affected versionversion=fdf24086f4752aee5dfb40143c736250df017820 <6e33a7eed587062ca8161ad1f4584882a860d697
  5. Affected versionversion=fdf24086f4752aee5dfb40143c736250df017820 <7b6a5b0a6b392263c3767fc945b311ea04b34bbd
  6. Affected versionversion=fdf24086f4752aee5dfb40143c736250df017820 <8eeb2091e72d75df8ceaa2172638d61b4cf8929a
  7. Affected versionversion=fdf24086f4752aee5dfb40143c736250df017820 <cfa7d9b1e3a8604afc84e9e51d789c29574fb216
  8. Affected versionversion=fdf24086f4752aee5dfb40143c736250df017820 <e1fcd4a9c09feac0902a65615e866dbf22616125
  9. Affected versionversion=fdf24086f4752aee5dfb40143c736250df017820 <fde6e73189f40ebcf0633aed2b68e731c25f3aa3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.37; version=fdf24086f4752aee5dfb40143c736250df017820 <0405055930264ea8fd26f4131466fa7652e5e47d; version=fdf24086f4752aee5dfb40143c736250df017820 <0627e1481676669cae2df0d85b5ff13e7d24c390; version=fdf24086f4752aee5dfb40143c736250df017820 <6e33a7eed587062ca8161ad1f4584882a860d697; version=fdf24086f4752aee5dfb40143c736250df017820 <7b6a5b0a6b392263c3767fc945b311ea04b34bbd; version=fdf24086f4752aee5dfb40143c736250df017820 <8eeb2091e72d75df8ceaa2172638d61b4cf8929a; version=fdf24086f4752aee5dfb40143c736250df017820 <cfa7d9b1e3a8604afc84e9e51d789c29574fb216; version=fdf24086f4752aee5dfb40143c736250df017820 <e1fcd4a9c09feac0902a65615e866dbf22616125; version=fdf24086f4752aee5dfb40143c736250df017820 <fde6e73189f40ebcf0633aed2b68e731c25f3aa3

Published CVSS scores

7.8LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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

T1068Exploitation for Privilege Escalation

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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