CVE-2026-23399: Linux kernel · Memory Leak
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium.
Data as of 26 Oct 2026, 14:05 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.
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 28 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
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux@6.17.0-40.40?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1019.19?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1020.20?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@6.17.0-1020.22?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle@6.17.0-1018.18?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 fix for this vulnerability is available in updated Linux kernel versions. Users should apply the official kernel updates provided by their distribution vendors, such as the Ubuntu security notice USN-8567-1. No additional mitigation actions are required beyond applying these patches.
Description
A memory leak vulnerability was resolved in the Linux kernel's nf_tables nft_dynset component. The issue occurs when cloning the second stateful expression with GFP_ATOMIC fails, leaving the first expression unreleased and causing a memory leak. This flaw affects multiple specific Linux kernel versions prior to 5.15.0-186.196 and certain exact builds. The vulnerability has a medium severity rating with an impact on availability but no confidentiality or integrity loss. A fix is available as part of Linux kernel updates.
References
- ubuntu.com/security/CVE-2026-23399 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-23399 (opens in a new tab)
- git.kernel.org/linus/0548a13b5a145b16e4da0628b5936baf35f51b43 (opens in a new tab)
- git.kernel.org/stable/c/0548a13b5a145b16e4da0628b5936baf35f51b43 (opens in a new tab)
- git.kernel.org/stable/c/31641c682db73353e4647e40735c7f2a75ff58ef (opens in a new tab)
- git.kernel.org/stable/c/c88a9fd26cee365bec932196f76175772a941cca (opens in a new tab)
- git.kernel.org/stable/c/d1354873cbe3b344899c4311ac05897fd83e3f21 (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)
- ubuntu.com/security/notices/USN-8606-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8607-1 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-23399 (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-019113.html (opens in a new tab)
- git.kernel.org/stable/c/4357dbb1d9c35ca0b4443d71c98a48e6666f7689 (opens in a new tab)
- git.kernel.org/stable/c/e6661add2d9c6913e1dad97336595e23a2bed195 (opens in a new tab)
- git.kernel.org/stable/c/eb7bf413e59945df03d4567b73ce464eebe2f4ea (opens in a new tab)