CVE-2025-39996

Kernel crash via unsynchronized FlexCop teardown

Published Oct 15, 2025 · Updated Oct 15, 2025

Use-after-free in the Linux B2C2 FlexCop PCI driver allows local users to crash the kernel during device removal. flexcop_pci_remove() calls cancel_delayed_work() and frees flexcop_device without waiting for a running irq_check_work callback to finish. Exploitation requires local low-privileged access and a B2C2 FlexCop PCI device-removal race; the documented consequence is a kernel crash.

CVSS severity5.5
Medium
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Use-after-free in the Linux B2C2 FlexCop PCI driver allows local users to crash the kernel during device removal. flexcop_pci_remove() calls cancel_delayed_work() and frees flexcop_device without waiting for a running irq_check_work callback to finish. Exploitation requires local low-privileged access and a B2C2 FlexCop PCI device-removal race; the documented consequence is a kernel crash.

The record

CVE
CVE-2025-39996
Published
Oct 15, 2025
Updated
Oct 15, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
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=2.6.29
  2. Affected versionversion=382c5546d618f24dc7d6ae7ca33412083720efbf <01e03fb7db419d39e18d6090d4873c1bff103914
  3. Affected versionversion=382c5546d618f24dc7d6ae7ca33412083720efbf <3ffabc79388e68877d9c02f724a0b7a38d519daf
  4. Affected versionversion=382c5546d618f24dc7d6ae7ca33412083720efbf <514a519baa9e2be7ddc2714bd730bc5a883e1244
  5. Affected versionversion=382c5546d618f24dc7d6ae7ca33412083720efbf <6a92f5796880f5aa345f0fed53ef511e3fd6f706
  6. Affected versionversion=382c5546d618f24dc7d6ae7ca33412083720efbf <bb10a9ddc8d6c5dbf098f21eb1055a652652e524
  7. Affected versionversion=382c5546d618f24dc7d6ae7ca33412083720efbf <d502df8a716d993fa0f9d8c00684f1190750e28e

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.29; version=382c5546d618f24dc7d6ae7ca33412083720efbf <01e03fb7db419d39e18d6090d4873c1bff103914; version=382c5546d618f24dc7d6ae7ca33412083720efbf <3ffabc79388e68877d9c02f724a0b7a38d519daf; version=382c5546d618f24dc7d6ae7ca33412083720efbf <514a519baa9e2be7ddc2714bd730bc5a883e1244; version=382c5546d618f24dc7d6ae7ca33412083720efbf <6a92f5796880f5aa345f0fed53ef511e3fd6f706; version=382c5546d618f24dc7d6ae7ca33412083720efbf <bb10a9ddc8d6c5dbf098f21eb1055a652652e524; version=382c5546d618f24dc7d6ae7ca33412083720efbf <d502df8a716d993fa0f9d8c00684f1190750e28e

Published CVSS scores

5.5OracleCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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

T1499.004Application or System Exploitation

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo