CVE-2025-38432: Linux kernel · net: netpoll: Initialize UDP checksum field before checksumming
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium.
Data as of 15 Nov 2026, 02:00 UTC
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 25 Jul 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 14 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-gcp-6.11pkg:deb/ubuntu/linux-gcp-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-hwe-6.11pkg:deb/ubuntu/linux-hwe-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-lowlatency-hwe-6.11pkg:deb/ubuntu/linux-lowlatency-hwe-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-raspi-realtimepkg:deb/ubuntu/linux-raspi-realtime?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-realtimepkg:deb/ubuntu/linux-realtime?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 is available that restores the initialization of the UDP checksum field before checksum calculation. Users should apply the updated Linux kernel versions that address this issue. Since this is a kernel-level vulnerability, upgrading to patched kernel releases is the recommended remediation.
Description
CVE-2025-38432 is a medium severity vulnerability in the Linux kernel's netpoll component affecting UDP checksum initialization. A recent code change removed the initialization of the UDP checksum field, causing incorrect checksum calculation and breaking netpoll IPv6 transmission. The issue arises because the UDP checksum field (udph->check) must be set before invoking the checksum calculation function csum_ipv6_magic(). This flaw impacts specific Linux kernel versions used in various Ubuntu LTS releases.
References
- ubuntu.com/security/CVE-2025-38432 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-38432 (opens in a new tab)
- git.kernel.org/linus/f5990207026987a353d5a95204c4d9cb725637fd (opens in a new tab)
- git.kernel.org/stable/c/353016ec159f939a380ff6746476a779367ba9a3 (opens in a new tab)
- git.kernel.org/stable/c/f5990207026987a353d5a95204c4d9cb725637fd (opens in a new tab)