CVE-2026-99071: Linux kernel · ipv4: do not warn on route notification size race
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 28 Oct 2026, 01:31 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
Exploitation 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 26.10linuxpkg: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 has been implemented that removes the incorrect warning while preserving proper error handling. Users should apply the updated Linux kernel versions that include this fix. No additional mitigation actions are required beyond updating to the fixed kernel versions.
Description
This vulnerability in the Linux kernel concerns a warning triggered by a race condition in route notification size handling. The issue arises when asynchronous route notifications for hardware flag changes are processed, potentially causing a legitimate size error that was previously misinterpreted as a bug. The fix removes the warning while maintaining error handling and notification to listeners.
References
- ubuntu.com/security/CVE-2026-99071 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-99071 (opens in a new tab)
- git.kernel.org/stable/c/088ba80eef85fa7a5ad8f9e7c82b403c99242b56 (opens in a new tab)
- git.kernel.org/stable/c/221ef5e1e44a044790f0f54e6aa237883f475a4d (opens in a new tab)
- git.kernel.org/stable/c/78a1cf5c54b2f795c81fedb530755a8d01cc84f0 (opens in a new tab)
- git.kernel.org/stable/c/7dfa7ca97f3ac46353edd4cc44f7733758e4535b (opens in a new tab)
- git.kernel.org/stable/c/e02a5b6588161673ef75a4bc5cdfb62bd493374d (opens in a new tab)