Description
In the Linux kernel, the following vulnerability has been resolved:

sctp: close UDP tunnel sockets during netns teardown

proc_sctp_do_udp_port() starts per-net SCTP UDP tunneling sockets when
net.sctp.udp_port is set, and stops/restarts them when the sysctl value
changes. The netns exit path does not stop these sockets, so a namespace
can be torn down while its SCTP UDP tunnel sockets are still installed.

Close the UDP tunnel sockets from sctp_ctrlsock_exit() after unregistering
the per-net sysctl table. This prevents new sysctl writes from racing in
while the sockets are being released, and closes the sockets before the
control socket is destroyed.
Published: 2026-08-10
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

The Linux kernel’s SCTP UDP tunneling mechanism left socket objects and associated kernel resources open when a network namespace was torn down. This oversight caused resource leaks—file descriptors, memory, and other kernel objects remained allocated, increasing the system’s resource footprint over time. Repeated creation and destruction of namespaces could cumulatively exhaust kernel resources, making the system unresponsive and enabling a denial‑of‑service condition. The vulnerability does not grant direct code execution or privilege escalation; its impact is confined to availability issues caused by resource exhaustion.

Affected Systems

Any Linux kernel system that enables SCTP UDP tunneling by setting the sysctl value net.sctp.udp_port to a non‑zero number is affected. The flaw is independent of a particular kernel release, as it persists until the patch that closes the sockets during namespace teardown is applied.

Risk and Exploitability

Exploitation requires the ability to create and destroy network namespaces, which is typically limited to privileged users or users with the CAP_SYS_ADMIN capability. Based on the description, it is inferred that the attacker must have local or privileged access to perform the exploit. The EPSS score is not available and the vulnerability is not listed in the CISA KEV catalog, indicating no known widespread exploitation. Nevertheless, for systems that enable SCTP UDP tunneling, the risk remains significant because the attack surface, while restricted to privileged actions, can lead to severe availability degradation.

Generated by OpenCVE AI on August 10, 2026 at 19:12 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Apply the latest Linux kernel patch that closes SCTP UDP tunnel sockets during network‑namespace teardown
  • If updating the kernel immediately is not possible, disable SCTP UDP tunneling by setting the sysctl net.sctp.udp_port to 0 so that no tunnel sockets are created
  • Plan and execute an upgrade to a kernel version that includes the fix

Generated by OpenCVE AI on August 10, 2026 at 19:12 UTC.

Tracking

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Advisories

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History

Mon, 10 Aug 2026 19:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-399

Mon, 10 Aug 2026 12:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: sctp: close UDP tunnel sockets during netns teardown proc_sctp_do_udp_port() starts per-net SCTP UDP tunneling sockets when net.sctp.udp_port is set, and stops/restarts them when the sysctl value changes. The netns exit path does not stop these sockets, so a namespace can be torn down while its SCTP UDP tunnel sockets are still installed. Close the UDP tunnel sockets from sctp_ctrlsock_exit() after unregistering the per-net sysctl table. This prevents new sysctl writes from racing in while the sockets are being released, and closes the sockets before the control socket is destroyed.
Title sctp: close UDP tunnel sockets during netns teardown
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: 2026-08-10T11:59:28.072Z

Reserved: 2026-07-30T09:28:09.372Z

Link: CVE-2026-68161

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-10T19:15:17Z

Weaknesses