CVE-2026-98017Public exploit

Local service interruption via qdisc use-after-free

Published Sep 25, 2026 · Updated Sep 25, 2026

Use-after-free in the Linux kernel traffic scheduler allows local users to crash the system through concurrent qdisc creation and traffic. clsact_init publishes an embedded mini_Qdisc to lockless readers, but an invalid TCA_RATE failure frees its qdisc while tc_run still holds it. Exploitation requires the affected scheduler options and unprivileged user and network namespaces; a successful race triggers a kernel memory-safety fault and service interruption.

CVSS severityUnavailable
Unscored
EPSS probability0.13%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux kernel traffic scheduler allows local users to crash the system through concurrent qdisc creation and traffic. clsact_init publishes an embedded mini_Qdisc to lockless readers, but an invalid TCA_RATE failure frees its qdisc while tc_run still holds it. Exploitation requires the affected scheduler options and unprivileged user and network namespaces; a successful race triggers a kernel memory-safety fault and service interruption.

The record

CVE
CVE-2026-98017
Published
Sep 25, 2026
Updated
Sep 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 25, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.16
  2. Affected versionversion=51ab2994c387c80b45caf8b8067b3f3b97771d25 <156a3bab69744e9225bb9eff8c5cc53da18d5a2e
  3. Affected versionversion=51ab2994c387c80b45caf8b8067b3f3b97771d25 <20bf6fa34b345333971bd4464a322cce87b83f4e
  4. Affected versionversion=51ab2994c387c80b45caf8b8067b3f3b97771d25 <5bfe927c5b4b290fad529186218c728589b4b101
  5. Affected versionversion=51ab2994c387c80b45caf8b8067b3f3b97771d25 <e6662f2100f8d33b0f4d0047c219efd6bba186ea

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.16; version=51ab2994c387c80b45caf8b8067b3f3b97771d25 <156a3bab69744e9225bb9eff8c5cc53da18d5a2e; version=51ab2994c387c80b45caf8b8067b3f3b97771d25 <20bf6fa34b345333971bd4464a322cce87b83f4e; version=51ab2994c387c80b45caf8b8067b3f3b97771d25 <5bfe927c5b4b290fad529186218c728589b4b101; version=51ab2994c387c80b45caf8b8067b3f3b97771d25 <e6662f2100f8d33b0f4d0047c219efd6bba186ea

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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