CVE-2026-68117

What it is

In the Linux kernel, the following vulnerability has been resolved: tipc: clear sock->sk on the failed-insert path in tipc_sk_create() When tipc_sk_create() fails to insert the new socket (tipc_sk_insert() returns non-zero), its error path frees the sk with sk_free() but leaves sock->sk pointing at the freed object: if (tipc_sk_insert(tsk)) { sk_free(sk); pr_warn("Socket create failed; port number exhausted\n"); return -EINVAL; } This is harmless for plain socket(): the syscall layer clears sock->ops before releasing, so tipc_release() is never called. It is not harmless on the accept() path. tipc_accept() creates the pre-allocated child socket with tipc_sk_create(net, new_sock, 0, kern); on failure it leaves new_sock->sk dangling and new_sock->ops non-NULL, and do_accept() then fput()s the new file, so __sock_release() -> tipc_release() runs lock_sock(new_sock->sk) on the freed sk -- a use-after-free write of the sk_lock spinlock. tipc_release() already guards this exact "failed accept() releases a pre-allocated child" case with "if (sk == NULL) return 0;", but the guard is bypassed because tipc_sk_create() left sock->sk non-NULL (dangling) rather than NULL. Clear sock->sk on the failed-insert path so the existing tipc_release() NULL check fires and the use-after-free is avoided. The tipc_sk_insert() failure is reached when the per-netns socket rhashtable hits its max_size (tsk_rht_params.max_size = 1048576, ~2M elements) -- i.e. once a netns holds ~2M TIPC sockets every insert returns -E2BIG. BUG: KASAN: slab-use-after-free in lock_sock_nested (net/core/sock.c:3839) Write of size 8 at addr ffff8880047cdc38 by task init/1 lock_sock_nested (net/core/sock.c:3839) tipc_release (net/tipc/socket.c:638) __sock_release (net/socket.c:710) sock_close (net/socket.c:1501) __fput (fs/file_table.c:512) Allocated by task 1: sk_alloc (net/core/sock.c:2308) tipc_sk_create (net/tipc/socket.c:487) tipc_accept (net/tipc/socket.c:2744) do_accept (net/socket.c:2034) Freed by task 1: __sk_destruct (net/core/sock.c:2391) tipc_sk_create (net/tipc/socket.c:504) tipc_accept (net/tipc/socket.c:2744) do_accept (net/socket.c:2034)

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2026-07-30 09:28 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-08-10 13:19 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-10-19 21:17 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.5% in the next 30 days (EPSS).
• Severity: 9.8 CRITICAL (CVSS).
• Fix: none linked yet, which raises it.

Details

Published

2026-08-10 13:19 UTC

Last modified

2026-10-19 21:17 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-416 · Use after free

Record status

Received

Attack profile CVSS 3.1 · 9.8

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-68117.md and follow it. Check whether this project is affected by CVE-2026-68117. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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