CVE-2026-23293: Linux kernel · net: vxlan: fix nd_tbl NULL dereference when IPv6 is disabled
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 5.15.0-1112.119~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 17:16 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.
- Patch
- Available – fixed in 5.15.0-1112.119~20.04.1, 5.15.0-1117.126~20.04.1, 5.15.0-1117.126~20.04.2 +63
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 Mar 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 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 patch is available and should be applied to affected Linux kernel versions. The vendor advisory from Ubuntu confirms that this issue has been fixed. Systems running affected versions should update to the patched kernel releases to remediate this vulnerability.
Description
A null pointer dereference vulnerability in the Linux kernel's VXLAN network driver occurs when IPv6 is disabled via the 'ipv6.disable=1' boot parameter. This happens because the nd_tbl is not initialized, leading to a kernel crash if an IPv6 packet is processed. The issue is fixed by adding an early check in the route_shortcircuit() function for IPv6 packets.
References
- ubuntu.com/security/CVE-2026-23293 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-23293 (opens in a new tab)
- git.kernel.org/linus/168ff39e4758897d2eee4756977d036d52884c7e (opens in a new tab)
- git.kernel.org/stable/c/168ff39e4758897d2eee4756977d036d52884c7e (opens in a new tab)
- git.kernel.org/stable/c/5f93e6b4d12bd3a4517a6d447ea675f448f21434 (opens in a new tab)
- git.kernel.org/stable/c/abcd48ecdeb2e12eccb8339a35534c757782afcd (opens in a new tab)
- git.kernel.org/stable/c/b5190fcd75a1f1785c766a8d1e44d3938e168f45 (opens in a new tab)
- git.kernel.org/stable/c/f0373e9317bc904e7bdb123d3106fe4f3cea2fb7 (opens in a new tab)
- git.kernel.org/stable/c/fbbd2118982c55fb9b0a753ae0cf7194e77149fb (opens in a new tab)
- ubuntu.com/security/notices/USN-8567-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8596-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8597-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-2 (opens in a new tab)