CVE-2026-74496
What it is
In the Linux kernel, the following vulnerability has been resolved: fou: Fix use-after-free in fou_create() fou_create() publishes struct fou through sk_user_data before adding the new FOU port to the per-netns list. If fou_add_to_port_list() fails, the error path frees fou while it is still reachable through sk_user_data. A concurrent receive can then dereference the freed object in fou_from_sock(). This ordering issue was previously noted in the linked discussion. The failure is reachable when local port 0 is requested. Each socket binds to a different ephemeral port, but fou_cfg_cmp() compares the requested port 0 and reports -EALREADY once an entry already exists. Release the tunnel socket before freeing fou so sk_user_data is cleared first, and defer reclamation with kfree_rcu() to protect concurrent RCU readers. This matches the lifetime handling in fou_release().
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.1% chance of exploitation in the next 30 days (EPSS).
- Fix
- No patch or advisory is linked yet. Look at mitigations or restrict exposure.
Timeline
- ReservedThe CVE id was reserved by its CNA
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.1% in the next 30 days (EPSS).
- Severity: 7.8 HIGH (CVSS).
- Fix: none linked yet, which raises it.
Details
- Published
- Last modified
- Exploit probability
- 0.1% · EPSS, next 30 days
- Record status
- Received
Attack profile CVSS 3.1 · 7.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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-2026-74496.md and follow it. Check whether this project is affected by CVE-2026-74496. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
References
- https://git.kernel.org/stable/c/0ee628a58d83e571f36ec9f07624d6845e420c50
- https://git.kernel.org/stable/c/58835985c035a8333742f829ad7e0889a082f9d3
- https://git.kernel.org/stable/c/9042867d4701728f0c6527215b11471759904d8f
- https://git.kernel.org/stable/c/99f4d3120b244f92e5df787152041296a2860cb5
- https://git.kernel.org/stable/c/a28d8903bfe76089ea4bbdbff9976965f9ef8107
- https://git.kernel.org/stable/c/a6fca682cfa2041e31aa72cc397c4a1406eb7468
- https://git.kernel.org/stable/c/b14361aca6350ff7907b0e9903c7b94dc7d5d4a0
- https://git.kernel.org/stable/c/b3f9c3e60aa25453774f899d25b5e61dd0bec1d5