CVE-2026-64120: Linux kernel · net: ethtool: fix NULL pointer dereference in phy_reply_size
Source 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 5% 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 19 Jul 2026
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
AI-suggested
Until a patch is applied, avoid conditions that could cause kstrdup() to fail in the affected code paths. Monitor for updates from the Linux kernel maintainers regarding an official fix.
Description
A NULL pointer dereference vulnerability in the Linux kernel's ethtool component was fixed. The issue occurs in the phy_prepare_data() function where memory allocation failures from kstrdup() were not checked, leading to a NULL pointer dereference and kernel panic in phy_reply_size(). This could cause a denial of service by crashing the kernel. The fix adds proper NULL checks and centralized error handling to prevent this condition.
References
- nvd.nist.gov/vuln/detail/CVE-2026-64120 (opens in a new tab)
- git.kernel.org/stable/c/3dbe20a3809347bacda890822e7ca013bd85a18c (opens in a new tab)
- git.kernel.org/stable/c/4908f1395fb1b832ceec11584af649874a2732ea (opens in a new tab)
- git.kernel.org/stable/c/61f53c1e58d68723bc1db10912a53f1991f08719 (opens in a new tab)