CVE-2026-98950: Linux kernel · flow_dissector: avoid u16 truncation of hlen in bpf_flow_dissect()
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 28 Oct 2026, 02:14 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 is available that caps the hlen value to the maximum u16 value before clamping in bpf_flow_dissect(). Users should apply the updated Linux kernel versions that include this fix. No additional mitigations are indicated.
Description
CVE-2026-98950 is a vulnerability in the Linux kernel's flow_dissector component where the hlen value used in bpf_flow_dissect() can be truncated due to u16 limits. This truncation causes offsets to be incorrectly clamped to zero when hlen exceeds 65535, potentially affecting packet flow dissection by BPF programs. The issue is similar to a previously fixed bug but affects the BPF path specifically. The vulnerability has been resolved by capping hlen to the maximum u16 value before clamping.
References
- ubuntu.com/security/CVE-2026-98950 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98950 (opens in a new tab)
- git.kernel.org/stable/c/3fb5ad2951a6df92c98f4f06cd70f20c50a2eb2a (opens in a new tab)
- git.kernel.org/stable/c/61b43a51a55929ec040bee3ea51af2121b956d05 (opens in a new tab)
- git.kernel.org/stable/c/c44c02c930c6583b235a1937c69ff716c4bb4514 (opens in a new tab)
- git.kernel.org/stable/c/cc18eb0e9941162c03f03f411ed7f6c339d91fa0 (opens in a new tab)
- git.kernel.org/stable/c/f202578efc738b883cfa04889eb97328914265a7 (opens in a new tab)