CVE-2026-68161 sctp: close UDP tunnel sockets during netns teardown
Attackers can cause a denial of service by tearing down network namespaces while SCTP UDP tunnel sockets remain active, requiring specific sysctl configuration.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-68161?
CVE-2026-68161 is a critical denial of service vulnerability in Linux, published on 10 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-404
Which versions are affected by CVE-2026-68161?
How do I fix CVE-2026-68161?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-68161 being exploited?
There is no known exploitation of CVE-2026-68161 in the wild and no public exploit code.
Sources
Also known as AZL-94950, BELL-CVE-2026-68161, DEBIAN-CVE-2026-68161, GHSA-9g3f-gj9q-hqjj, UBUNTU-CVE-2026-68161.