CVE-2026-64542: Linux kernel · ipv6: ndisc: fix NULL deref in accept_untracked_na()
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 7.0.0-38.38~24.04.4 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 13:47 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0-38.38~24.04.4, 7.0.0-38.38, 7.0.0-1014.14 +11
Exploitation evidence
Disclosed: evidence found.
CVE published 27 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
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther 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 patch is available and should be applied to affected Linux kernel versions. The vendor advisory from Ubuntu confirms that the issue has been fixed. Users should update their systems to the fixed kernel versions and reboot to apply the changes. No additional mitigation steps are indicated.
Description
A NULL pointer dereference vulnerability in the Linux kernel's IPv6 Neighbor Discovery (ndisc) subsystem was fixed. The issue occurs in the accept_untracked_na() function, which re-fetches a device pointer without a NULL check, potentially causing a kernel crash. This vulnerability is reachable by an unprivileged user via a network namespace. The flaw was addressed by using the already validated device pointer instead of re-fetching it. A patch is available to fix this issue.
References
- ubuntu.com/security/CVE-2026-64542 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64542 (opens in a new tab)
- git.kernel.org/linus/d186e942365acece7c56d39da05dd63bf95b280a (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-64542 (opens in a new tab)
- git.kernel.org/stable/c/160d3f0d7a556ceae505dcab521a37057b4ce28f (opens in a new tab)
- git.kernel.org/stable/c/62c719203cb521b64fab74da94a81bdde5c18808 (opens in a new tab)
- git.kernel.org/stable/c/63d1c23764de2309cedbb779c75188d257a09d9b (opens in a new tab)
- git.kernel.org/stable/c/a6450f7cfae57b382cbaf66a577765c9a88b3c58 (opens in a new tab)
- git.kernel.org/stable/c/d186e942365acece7c56d39da05dd63bf95b280a (opens in a new tab)
- msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-64542.json (opens in a new tab)
- support.microsoft.com/lifecycle (opens in a new tab)
- first.org/cvss (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-3 (opens in a new tab)