# CVE-2026-90110

Linux kernel inetpeer RB-tree predictability allows off‑path rate‑limit bypass & UDP port inference

- Page: https://www.vulneraibility.com/cve/CVE-2026-90110
- CVSS: 9.4
- Known exploited: not in CISA KEV as of our last sync
- EPSS: 0.61% (percentile 49.4)
- Published: 2026-09-17

## Affected versions

- Linux: affected >= b145425f269a17ed344d737f746b844dfac60c82 and < b20e98f0bb668a59abaf7bcf85d75c073e90d352; >= b145425f269a17ed344d737f746b844dfac60c82 and < 5f127e3cc9647a8a70db12c65dbd0de473545380; >= b145425f269a17ed344d737f746b844dfac60c82 and < 199fcf285e498111e029137d088949bc6c26d578; >= b145425f269a17ed344d737f746b844dfac60c82 and < 857681f6835d5b0a7bc4a34a026baeaaf5215623; >= b145425f269a17ed344d737f746b844dfac60c82 and < 7109bb63667a53e4542ad845476f97d0c8b28a61; >= b145425f269a17ed344d737f746b844dfac60c82 and < 2ee66e9487172fcd189bc52a767c30dad7141c09; 4.14; fixed in < 4.14, >= 6.1.188 and <= 6.1.*, >= 6.6.157 and <= 6.6.*, >= 6.12.110 and <= 6.12.*, >= 6.18.52 and <= 6.18.*, >= 7.2.6 and <= 7.2.*, >= 7.3-rc1 and <= *

A version outside these ranges is not a statement that it is unaffected.

## Impact

Off‑path attackers can bypass IP‑keyed ICMP/UDP rate limits and infer open UDP ports, enabling reconnaissance and potential abuse of UDP services.

## Action

Immediate action required

## Recommendation

Apply vendor/upstream kernel updates with the inetpeer fix and reboot affected hosts.

## References

- [other] https://git.kernel.org/stable/c/b20e98f0bb668a59abaf7bcf85d75c073e90d352
- [other] https://git.kernel.org/stable/c/5f127e3cc9647a8a70db12c65dbd0de473545380
- [other] https://git.kernel.org/stable/c/199fcf285e498111e029137d088949bc6c26d578
- [other] https://git.kernel.org/stable/c/857681f6835d5b0a7bc4a34a026baeaaf5215623
- [other] https://git.kernel.org/stable/c/7109bb63667a53e4542ad845476f97d0c8b28a61
- [other] https://git.kernel.org/stable/c/2ee66e9487172fcd189bc52a767c30dad7141c09

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Summary, impact and action are written by the vulneraibility.com AI analysis pipeline from the CVE record, NVD, CISA and FIRST data; verify against the references.