SB20260816222 - Use-after-free in Linux kernel ipv4

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-74496)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to use-after-free in fou_create() and fou_from_sock() when handling concurrent socket activity after a failed FOU port creation. A local user can request local port 0 and trigger concurrent receive processing to cause a denial of service.

The issue is reachable when local port 0 is requested and the creation path fails after the object remains reachable through sk_user_data.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/a28d8903bfe76089ea4bbdbff9976965f9ef8107
• https://git.kernel.org/stable/c/b14361aca6350ff7907b0e9903c7b94dc7d5d4a0