SB20260912112 - Use-after-free in Linux kernel nfsd



SB20260912112 - Use-after-free in Linux kernel nfsd

Published: September 12, 2026

Security Bulletin ID SB20260912112
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Information disclosure

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Use-after-free (CVE-ID: CVE-2026-89669)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 0 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to trigger a use-after-free condition.

The vulnerability exists due to a use-after-free in copy-notify state initialization when racing a crafted OFFLOAD_CANCEL request against COPY_NOTIFY processing. A remote attacker can send a crafted OFFLOAD_CANCEL request to trigger a use-after-free condition.

Exploitation requires a matching client ID and a guessable state object ID.


Remediation

Install update from vendor's website.