SB20260918116 - Improper update of reference count in Linux kernel ipv6

Description

This security bulletin contains information about 1 vulnerability.

1) Improper update of reference count (CVE-ID: CVE-2026-93105)

CWE-ID: CWE-911 - Improper Update of Reference Count

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 free a page that is still in use.

The vulnerability exists due to improper reference count handling in the ESP esp_ssg_unref() function when processing an ESP packet with managed fragments during an AEAD operation. A local user can process an ESP packet with managed fragments to free a page that is still in use.

Managed fragments can be attached through io_uring SEND_ZC with a registered buffer.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/21697720ff43b8dfa25b8e8d9ca7f56f4597fc80
• https://git.kernel.org/stable/c/26b6b14c7a0368e317a1e9fb5144ebe6f8d495cf