CVE-2025-39987: Linux kernel · can: hi311x: populate ndo_change_mtu() to prevent buffer overflow
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.15.0-1100.107~20.04.2 : patch Linux kernel soon.
Data as of 28 Oct 2026, 11:20 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:U/C:H/I:H/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 fix is available and included in Linux kernel versions 5.15.0-1094.97~20.04.1 and later patched releases. Users should update to these fixed kernel versions to mitigate the vulnerability. The patch populates the ndo_change_mtu() function to enforce valid MTU settings, preventing buffer overflow conditions. No additional mitigations are required beyond applying the official kernel updates and rebooting the system.
Description
CVE-2025-39987 is a vulnerability in the Linux kernel's CAN driver (hi311x) where the lack of proper MTU validation allows an attacker to set an invalid MTU value. This enables sending malicious CAN XL frames via PF_PACKET sockets that bypass CAN framework checks, leading to a buffer overflow in the hi3110_hard_start_xmit() function. The issue is fixed by populating the ndo_change_mtu() operation to restrict MTU values to valid limits.
References
- ubuntu.com/security/CVE-2025-39987 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-39987 (opens in a new tab)
- git.kernel.org/linus/ac1c7656fa717f29fac3ea073af63f0b9919ec9a (opens in a new tab)
- git.kernel.org/stable/c/57d332ce8c921d0e340650470bb0c1d707f216ee (opens in a new tab)
- git.kernel.org/stable/c/7ab85762274c0fa997f0ef9a2307b2001aae43c4 (opens in a new tab)
- git.kernel.org/stable/c/8f351db6b2367991f0736b2cff082f5de4872113 (opens in a new tab)
- git.kernel.org/stable/c/ac1c7656fa717f29fac3ea073af63f0b9919ec9a (opens in a new tab)
- git.kernel.org/stable/c/be1b25005fd0f9d4e78bec6695711ef87ee33398 (opens in a new tab)
- git.kernel.org/stable/c/def814b4ba31b563584061d6895d5ff447d5bc14 (opens in a new tab)
- git.kernel.org/stable/c/e77fdf9e33a83a08f04ab0cb68c19ddb365a622f (opens in a new tab)
- git.kernel.org/stable/c/f2c247e9581024d8b3dd44cbe086bf2bebbef42c (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)