CVE-2026-98603
Received Received - Intake

ovpn Route Lookup Failure with IPv6 Address Corruption

Publication date: 2026-10-18

Last updated on: 2026-10-18

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: ovpn: replace bind when clearing stale local source The UDP output fallback clears bind->local in place when the remembered source address is no longer usable. The bind is RCU-published and read locklessly by concurrent TX, so an IPv6 reader can observe a torn address. Retry the route lookup with source address autoselection without modifying the bind. After a successful lookup, revalidate the bind and route key under peer->lock, reset the dst cache, and best-effort publish a replacement bind with a wildcard local address. Do not cache the resolved dst when clearing the local source. Replacing the source invalidates all per-CPU cache entries, while dst_cache_set_ip4 and dst_cache_set_ip6 update only the current CPU slot. The current packet can still use the resolved route; if bind allocation fails, a later cache miss retries the repair.

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Meta Information

Published
2026-10-18
Last Modified
2026-10-18
Generated
2026-10-18
AI Q&A
2026-10-18
EPSS Evaluated
N/A
NVD
CVE-2026-98603
EUVD
EUVD-2026-103648

Affected Vendors & Products

Showing 4 associated CPEs
Vendor Product Version / Range
Linux Linux 08857b5ec5d91d83e69e40a36554a8c7557b7301
Linux Linux 08857b5ec5d91d83e69e40a36554a8c7557b7301
Linux Linux 08857b5ec5d91d83e69e40a36554a8c7557b7301
Linux Linux 6.16

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Exploitability

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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in the Linux kernel involves a race condition in the OpenVPN (ovpn) UDP output fallback mechanism. When clearing a stale local source address, the bind structure is modified in place while being accessed concurrently by IPv6 readers. This can lead to a torn address being observed, causing potential data corruption or crashes due to inconsistent state.

Impact Analysis

This vulnerability may cause system instability, crashes, or unexpected behavior in systems using the Linux kernel with OpenVPN. Attackers could exploit the race condition to trigger denial-of-service conditions or corrupt network operations, potentially leading to service disruptions.

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