CVE-2026-74406: Linux kernel · vxlan: Fix potential null-ptr-deref in vxlan_gro_prepare_receive().
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 9.8 Critical · fixed in f79c80f173fda9545b220c1f094b65fc06c252d0 : patch Linux kernel as a priority.
Data as of 30 Oct 2026, 13:19 UTC
Thin evidence
One scorer or none| CNA (Linux) | CVSS 3.1 | 9.8 |
|---|
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers can reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in f79c80f173fda9545b220c1f094b65fc06c252d0, ef44dac2a37f86eeae6b88ed10a6d60b35387dfd, a3104cc1fed994519538301efcaab175f9af6008 +5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 15 Aug 2026
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 30 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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AI-suggested
This vulnerability has been fixed in the Linux kernel in the commits identified by hashes f79c80f173fda9545b220c1f094b65fc06c252d0, ef44dac2a37f86eeae6b88ed10a6d60b35387dfd, a3104cc1fed994519538301efcaab175f9af6008, 30a45c0bffdd62350261e2f2689fdba426a33578, 022af89207fcc992ec5c712c14e2e018c335eb1e, 9c58c729d32e7cea5772cc44929c6cd61e5a31cd, 08f40c0d23c67c3aa4224c3311e134999c721fb4, and 4a8cde6f7281ea2c4c290f9ad9923b3631defceb. Users and administrators should update affected Linux kernel versions to incorporate these fixes. No additional mitigation steps are indicated.
Description
CVE-2026-74406 is a critical vulnerability in the Linux kernel's VXLAN implementation. It involves a potential null pointer dereference in the function vxlan_gro_prepare_receive(). The issue arises because udp_tunnel_sock_release() can set sk->sk_user_data to NULL while vxlan_gro_prepare_receive() is executing, leading to a null pointer dereference after skb_gro_remcsum_init(). This flaw has been fixed in several Linux kernel commits.
References
- git.kernel.org/stable/c/022af89207fcc992ec5c712c14e2e018c335eb1e (opens in a new tab)
- git.kernel.org/stable/c/a3104cc1fed994519538301efcaab175f9af6008 (opens in a new tab)
- git.kernel.org/stable/c/9c58c729d32e7cea5772cc44929c6cd61e5a31cd (opens in a new tab)
- git.kernel.org/stable/c/f79c80f173fda9545b220c1f094b65fc06c252d0 (opens in a new tab)
- git.kernel.org/stable/c/08f40c0d23c67c3aa4224c3311e134999c721fb4 (opens in a new tab)
- git.kernel.org/stable/c/4a8cde6f7281ea2c4c290f9ad9923b3631defceb (opens in a new tab)
- git.kernel.org/stable/c/ef44dac2a37f86eeae6b88ed10a6d60b35387dfd (opens in a new tab)
- git.kernel.org/stable/c/30a45c0bffdd62350261e2f2689fdba426a33578 (opens in a new tab)