CVE-2025-38443: Linux kernel · nbd: fix uaf in nbd_genl_connect() error path
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in d46186eb7bbd9a11c145120f2d77effa8d4d44c2 : patch Linux kernel soon.
Data as of 5 Nov 2026, 21:20 UTC
Rated High by Threat Radar's AI analysis · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-11-05.
- Patch
- Available – fixed in d46186eb7bbd9a11c145120f2d77effa8d4d44c2, cb121c47f364b51776c4db904a6a5a90ab0a7ec5, aa9552438ebf015fc5f9f890dbfe39f0c53cf37e +3
Exploitation evidence
Disclosed: evidence found.
CVE published 25 Jul 2025
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 5 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
AI-suggested
A fix is available and has been applied in the Linux kernel source code as indicated by the fixed commit hashes. Users and administrators should update to a Linux kernel version that includes these fixes. Since this is not a cloud service, manual patching or kernel upgrade is required to remediate this vulnerability.
Description
A use-after-free vulnerability exists in the Linux kernel's nbd driver in the nbd_genl_connect() error path. The issue occurs because the device is not properly stopped on certain error paths after nbd_start_device() has been called, leading to use of freed memory by recv_work. This flaw has been fixed by moving nbd_start_device() after backend file creation.
References
- git.kernel.org/stable/c/cb121c47f364b51776c4db904a6a5a90ab0a7ec5 (opens in a new tab)
- git.kernel.org/stable/c/91fa560c73a8126868848ed6cd70607cbf8d87e2 (opens in a new tab)
- git.kernel.org/stable/c/d46186eb7bbd9a11c145120f2d77effa8d4d44c2 (opens in a new tab)
- git.kernel.org/stable/c/8586552df591e0a367eff44af0c586213eeecc3f (opens in a new tab)
- git.kernel.org/stable/c/002aca89753f666d878ca0eb8584c372684ac4ba (opens in a new tab)
- git.kernel.org/stable/c/aa9552438ebf015fc5f9f890dbfe39f0c53cf37e (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/10/msg00008.html (opens in a new tab)