CVE-2025-39925: Linux kernel · can: j1939: implement NETDEV_UNREGISTER notification handler
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 1 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
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux@6.8.0-136.136?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws@6.8.0-1060.63?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14@6.14.0-1018.18~24.04.1?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure@6.8.0-1062.69?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11@6.11.0-1018.18~24.04.1?arch=source&distro=nobleOther 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 fix has been implemented in the Linux kernel to add the missing NETDEV_UNREGISTER notification handler for the J1939 protocol. Users should update to a patched kernel version containing this fix. No additional mitigation steps are indicated.
Description
A vulnerability in the Linux kernel's CAN J1939 protocol implementation was resolved by adding a NETDEV_UNREGISTER notification handler. The issue involved an extra reference count held by j1939_sk_bind() that prevented the network device from unregistering properly, causing unregister_netdevice() to hang. This was fixed by ensuring the extra reference is released when the NETDEV_UNREGISTER notification fires.
References
- ubuntu.com/security/CVE-2025-39925 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-39925 (opens in a new tab)
- git.kernel.org/linus/7fcbe5b2c6a4b5407bf2241fdb71e0a390f6ab9a (opens in a new tab)
- git.kernel.org/stable/c/7fcbe5b2c6a4b5407bf2241fdb71e0a390f6ab9a (opens in a new tab)
- git.kernel.org/stable/c/da9e8f429139928570407e8f90559b5d46c20262 (opens in a new tab)