CVE-2025-68372: Linux kernel · nbd: defer config put in recv_work
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 5.15.0-1103.110~20.04.1 : 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 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1103.110~20.04.1, 5.15.0-1110.119~20.04.1, 5.15.0-1103.112~20.04.1 +70
Exploitation evidence
Disclosed: evidence found.
CVE published 24 Dec 2025
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@6.17.0-19.19?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1009.9?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1010.10?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp@6.17.0-1009.9?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle@6.17.0-1009.9?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 to resolve the use-after-free vulnerability in the nbd driver. The fix involves moving the nbd_config_put call to the end of the recv_work function to maintain proper reference counting and prevent premature freeing. Users should update to the fixed kernel versions as indicated in the vendor advisory. No additional mitigations are specified or required beyond applying the official fix.
Description
A use-after-free (UAF) vulnerability was identified and resolved in the Linux kernel's network block device (nbd) driver, specifically in the recv_work function when handling certain socket and reconfiguration commands. The flaw involves improper reference counting leading to premature freeing of configuration data while worker threads are still active. This could cause system instability or crashes. The issue has been fixed by adjusting the timing of the config put operation to ensure the reference remains valid for the lifetime of the worker thread. Multiple affected Linux kernel versions used in Azure environments are addressed by this fix.
References
- ubuntu.com/security/CVE-2025-68372 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-68372 (opens in a new tab)
- git.kernel.org/stable/c/443a1721806b6ff6303b5229e9811d68172d622f (opens in a new tab)
- git.kernel.org/stable/c/6b69593f72e1bfba6ca47ca8d9b619341fded7d6 (opens in a new tab)
- git.kernel.org/stable/c/742012f6bf29553fdc460bf646a58df3a7b43d01 (opens in a new tab)
- git.kernel.org/stable/c/9517b82d8d422d426a988b213fdd45c6b417b86d (opens in a new tab)
- ubuntu.com/security/notices/USN-8094-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8096-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8096-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8094-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8096-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8096-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8116-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8096-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8094-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8094-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8094-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8141-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8152-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8163-1 (opens in a new tab)