CVE-2025-39875: Linux kernel · igb: Fix NULL pointer dereference in ethtool loopback test
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 2% 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 23 Sep 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?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14?arch=source&distro=nobleOther threats | 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-azure-6.14pkg:deb/ubuntu/linux-azure-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-fde-6.14pkg:deb/ubuntu/linux-azure-fde-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-nvidia-6.14pkg:deb/ubuntu/linux-azure-nvidia-6.14?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.
Description
In the Linux kernel, the following vulnerability has been resolved: igb: Fix NULL pointer dereference in ethtool loopback test The igb driver currently causes a NULL pointer dereference when executing the ethtool loopback test. This occurs because there is no associated q_vector for the test ring when it is set up, as interrupts are typically not added to the test rings. Since commit 5ef44b3cb43b removed the napi_id assignment in __xdp_rxq_info_reg(), there is no longer a need to pass a napi_id to it. Therefore, simply use 0 as the last parameter.
References
- ubuntu.com/security/CVE-2025-39875 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-39875 (opens in a new tab)
- git.kernel.org/linus/75871a525a596ff4d16c4aebc0018f8d0923c9b1 (opens in a new tab)
- git.kernel.org/stable/c/473be7d39efd3be383e9c0c8e44b53508b4ffeb5 (opens in a new tab)
- git.kernel.org/stable/c/75871a525a596ff4d16c4aebc0018f8d0923c9b1 (opens in a new tab)