SB2026072723 - Use-after-free in Linux kernel sched

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Main Vulnerability Database SB2026072723

SB2026072723 - Use-after-free in Linux kernel sched

Published: July 27, 2026

Security Bulletin ID SB2026072723
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Use-after-free (CVE-ID: CVE-2026-64530)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 6 [CVSS:4.0/AV:N/AC:L/AT:P/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 a use-after-free in tcf_qevent_handle in net/sched/cls_api.c when handling TC_ACT_CONSUMED during qevent processing of fragmented traffic. A local user can send specially crafted fragmented network traffic to trigger use of an skb after ownership has been transferred and cause a denial of service.

Exploitation requires RED qdisc qevents together with ct defragmentation and traffic that produces out-of-order fragments.


Remediation

Install update from vendor's website.

References