CVE-2025-38666: Linux kernel · net: appletalk: Fix use-after-free in AARP proxy probe
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 4.4.0-1150.156 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- 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 4.4.0-1150.156, 4.15.0-1195.210~14.04.1, 4.4.0-276.310~14.04.1 +106
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 22 Aug 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.
Patches and advisories
- ubuntu.com/security/notices/USN-7879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7880-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7907-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7907-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7909-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7909-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7909-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7910-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7907-3 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther 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 has been incorporated into Linux kernel updates. Users should apply the latest kernel updates as provided by their Linux distribution vendors, such as Ubuntu's security notices USN-7879-1 and USN-7879-2. After updating, a system reboot is required to complete remediation. Due to ABI changes, recompilation and reinstallation of third-party kernel modules may be necessary. No alternative mitigations are indicated by the vendor advisory.
Description
A use-after-free vulnerability in the Linux kernel's Appletalk protocol was identified and resolved. The flaw occurs in the AARP proxy-probe routine where a race condition between releasing and re-acquiring a lock allows an expire timer thread to free an entry that is still in use. This can lead to memory corruption. The vulnerability has a high severity score of 7.8 and affects many Linux kernel versions prior to 6.14.0-36.36 and related builds. A patch is available and included in updated Linux kernel packages. Users are advised to update and reboot to apply the fix.
References
- ubuntu.com/security/CVE-2025-38666 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-38666 (opens in a new tab)
- git.kernel.org/linus/6c4a92d07b0850342d3becf2e608f805e972467c (opens in a new tab)
- git.kernel.org/stable/c/2a6209e4649d45fd85d4193abc481911858ffc6f (opens in a new tab)
- git.kernel.org/stable/c/5f02ea0f63dd38c41539ea290fcc1693c73aa8e5 (opens in a new tab)
- git.kernel.org/stable/c/6c4a92d07b0850342d3becf2e608f805e972467c (opens in a new tab)
- git.kernel.org/stable/c/e4f1564c5b699eb89b3040688fd6b4e57922f1f6 (opens in a new tab)
- git.kernel.org/stable/c/f90b6bb203f3f38bf2b3d976113d51571df9a482 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7880-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7907-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7907-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7909-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7909-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7909-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7910-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7907-3 (opens in a new tab)