CVE-2026-99201: Linux kernel · netlink: avoid hashing the network namespace pointer
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 29 Oct 2026, 22:38 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
Thin evidence
One scorer or noneExploitation evidence
Disclosed: evidence found.
CVE published 28 Oct 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 29 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10linuxpkg:deb/ubuntu/linux?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=stonkingOther 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 is available and has been backported to Linux kernel versions 5.15 and later. Users should upgrade to a patched kernel version that replaces the raw network namespace pointer with the net_cookie in the netlink hash key. No additional mitigation is required beyond applying the official kernel update.
Description
CVE-2026-99201 is a vulnerability in the Linux kernel's netlink subsystem where the network namespace pointer was hashed in a way that could leak kernel address information. An unprivileged user could exploit this to recover parts of the kernel memory layout. The issue is fixed by replacing the raw pointer with a unique, non-address net_cookie value in the hash key, preventing address leakage. The fix is backported to stable kernels from version 5.15 onward.
References
- ubuntu.com/security/CVE-2026-99201 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-99201 (opens in a new tab)
- git.kernel.org/stable/c/f88bb3606e4bd11ee035b682cddc2999e604609a (opens in a new tab)
- git.kernel.org/stable/c/bdd55b8a8acbf6b4840ab420eb6a63774bf4593b (opens in a new tab)
- git.kernel.org/stable/c/078deff25f8a849ecd1c3fe17b1e473b1cf44f28 (opens in a new tab)