# CVE-2026-98849: pfcp: fix socket lifetime on netdevice registration failure

> A local attacker can trigger a kernel crash via a double-free scenario in the PFCP module when netdevice registration fails.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-98849, DEBIAN-CVE-2026-98849, GHSA-gh42-phxg-w86j, UBUNTU-CVE-2026-98849

## What is CVE-2026-98849?

CVE-2026-98849 is a vulnerability in Linux, published on 18 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

pfcp: fix socket lifetime on netdevice registration failure

pfcp_newlink() creates the UDP socket before register_netdevice().
If registration fails after pfcp_dev_init() succeeds, the core calls
pfcp_dev_uninit(), which releases the socket and clears pfcp->sk.
The newlink error path then releases it again, causing a NULL pointer
dereference. This was observed with failslab fault injection:

  FAULT_INJECTION: forcing a failure.
  kobject: kobject_add_internal failed for pfcp0 (error: -12 parent: net)
  BUG: KASAN: null-ptr-deref in udp_tunnel_sock_release+0x1c/0x50
  Read of size 8 at addr 0000000000000120 by task ip/1037
  Call trace:
   show_stack+0x18/0x24 (C)
   dump_stack_lvl+0x78/0x90
   print_report+0x468/0x5cc
   kasan_report+0xa4/0xf0
   __asan_load8+0x7c/0xd0
   udp_tunnel_sock_release+0x1c/0x50
   pfcp_newlink+0x128/0x184
   rtnl_newlink+0x848/0xe44
   rtnetlink_rcv_msg+0x468/0x514
   netlink_rcv_skb+0xc0/0x1f0
   rtnetlink_rcv+0x18/0x24
   netlink_unicast+0x4b8/0x558
   netlink_sendmsg+0x2b8/0x584
   ...

Return from pfcp_del_sock() if pfcp->sk is NULL.

## Which versions are affected by CVE-2026-98849?


## How do I fix CVE-2026-98849?

Apply the vendor's patch.

## Is CVE-2026-98849 being exploited?

There is no known exploitation of CVE-2026-98849 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98849 and fix it if it is affected.

What it is: CVE-2026-98849 is a vulnerability in Linux, published on 18 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-98849 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-98849/ (Markdown: https://insights.sbomify.com/CVE-2026-98849/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98849
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98849
- OSV: https://osv.dev/vulnerability/CVE-2026-98849

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98849/
Summaries are generated and may contain mistakes; the official description above is the record.