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.
Published: 2026-10-18
Score: n/a
EPSS: n/a
KEV: No
Impact: Memory corruption and system instability from concurrent access to bind structures
Action: Immediate Patch
AI Analysis

Impact

In the Linux kernel a race condition exists when the UDP output fallback clears the bind's local address in place. The bind is published via RCU and read locklessly by other traffic, so an IPv6 reader can observe a torn address. This can cause invalid memory accesses, route lookup failures and potentially kernel instability or crashes. The weakness is a race condition that may lead to memory corruption (CWE‑1003, CWE‑119).

Affected Systems

Any Linux kernel installation that incorporates the vulnerable binding code is affected. The advisory does not list specific version ranges, so all kernel versions prior to the patch referenced in the coupled commit are considered at risk, regardless of distribution.

Risk and Exploitability

The vulnerability has no reported public exploits and its EPSS score is unavailable, indicating a low to moderate likelihood of active exploitation. It is not listed in CISA KEV. As it requires concurrent access to kernel memory, a local or privileged attacker who can induce the specific UDP dispatch path would be able to trigger the race and exploit it. In the absence of confirmed exploits, the risk is primarily theoretical but should be mitigated with the available patch.

Generated by OpenCVE AI on October 18, 2026 at 18:33 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade the Linux kernel to the latest stable release that contains the commit clearing the bind in a safe manner (e.g., the commit referenced in the advisory).
  • Reboot the system after applying the patch so that the updated kernel code is loaded and all memory contexts are refreshed.
  • Verify that network traffic has resumed normal operation and that kernel logs no longer report bind‑related corruption or panics.

Generated by OpenCVE AI on October 18, 2026 at 18:33 UTC.

Tracking

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Advisories

No advisories yet.

History

Sun, 18 Oct 2026 19:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-1003
CWE-119

Sun, 18 Oct 2026 15:30:00 +0000

Type Values Removed Values Added
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.
Title ovpn: replace bind when clearing stale local source
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-18T15:19:16.215Z

Reserved: 2026-09-25T10:25:14.359Z

Link: CVE-2026-98603

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-18T16:17:13.040

Modified: 2026-10-18T16:17:13.040

Link: CVE-2026-98603

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-18T18:45:06Z

Weaknesses
  • CWE-1003
  • CWE-119

    Improper Restriction of Operations within the Bounds of a Memory Buffer