CVE-2026-23105
Unknown Unknown - Not Provided
Inconsistent Class Activation Check in Linux Kernel QFQ Scheduler

Publication date: 2026-02-04

Last updated on: 2026-04-03

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: net/sched: qfq: Use cl_is_active to determine whether class is active in qfq_rm_from_ag This is more of a preventive patch to make the code more consistent and to prevent possible exploits that employ child qlen manipulations on qfq. use cl_is_active instead of relying on the child qdisc's qlen to determine class activation.
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Meta Information
Published
2026-02-04
Last Modified
2026-04-03
Generated
2026-06-16
AI Q&A
2026-02-04
EPSS Evaluated
2026-06-15
NVD
CVE-2026-23105
Affected Vendors & Products
Showing 12 associated CPEs
Vendor Product Version / Range
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel From 3.8 (inc) to 5.10.249 (exc)
linux linux_kernel From 5.11 (inc) to 5.15.199 (exc)
linux linux_kernel From 5.16 (inc) to 6.1.162 (exc)
linux linux_kernel From 6.2 (inc) to 6.6.122 (exc)
linux linux_kernel From 6.7 (inc) to 6.12.68 (exc)
linux linux_kernel From 6.13 (inc) to 6.18.8 (exc)
linux linux_kernel 6.19
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Exploitability
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CWE ID Description
CWE-UNKNOWN
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Executive Summary

This vulnerability relates to the Linux kernel's network scheduler component, specifically the qfq (Quick Fair Queueing) module. The issue was that the code used the child queue length (qlen) to determine whether a class was active, which could be manipulated. The patch changes this behavior to use the cl_is_active function instead, making the determination of class activity more consistent and preventing potential exploits that manipulate child qlen.

Impact Analysis

If exploited, this vulnerability could allow attackers to manipulate the network scheduler's behavior by altering the child queue length, potentially leading to inconsistent or unintended network traffic handling. This could affect network performance or fairness in traffic scheduling.

Compliance Impact

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Detection Guidance

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