CVE-2026-98899: Linux kernel · netfilter: ipset: mark the rcu locked areas properly
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 28 Oct 2026, 02:14 UTC
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 23 Oct 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 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther 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
The vulnerability has been resolved in updated Linux kernel versions. Users should apply the official kernel updates that fix the RCU locking issues in the netfilter ipset subsystem. Since this is a kernel-level flaw, patching the kernel to a fixed version is the recommended mitigation. No information about workarounds or temporary mitigations is provided.
Description
A high-severity vulnerability in the Linux kernel's netfilter ipset subsystem involves improper marking of RCU locked areas. The issue relates to the handling of reference counters and locking mechanisms, which could impact confidentiality, integrity, and availability of affected systems. Multiple specific Linux kernel versions are affected.
References
- ubuntu.com/security/CVE-2026-98899 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98899 (opens in a new tab)
- git.kernel.org/stable/c/0c46c9ce24130657ec7460c27fba5d445f5abd06 (opens in a new tab)
- git.kernel.org/stable/c/5d0c22e73656d050daffad10a2ba8765ce8441c8 (opens in a new tab)
- git.kernel.org/stable/c/67bd3d2350d17c2f4fb158c3f917c10b15ecbc94 (opens in a new tab)
- git.kernel.org/stable/c/892399abd1a005a455d5b74d86d82b9773405f2b (opens in a new tab)
- git.kernel.org/stable/c/ca9fab1ca15534cef1630e81a479e94b3bbcdb6a (opens in a new tab)
- git.kernel.org/stable/c/ecb48c6b9edc78de8dd456c365727ae14b88c1ee (opens in a new tab)
- git.kernel.org/stable/c/eee5172741b2c0e73210020732043e5d589295d3 (opens in a new tab)