Local denial of service via unclamped quantum
Published Sep 25, 2026 · Updated Sep 25, 2026
Denial of service in affected Linux kernels allows local users to trigger a soft lockup through a crafted fq_pie queue discipline. fq_pie_change() accepts a user-supplied quantum of 1, letting a crafted size table inflate qdisc_pkt_len to about 2 GiB and force roughly 2^31 deficit-refill iterations while the qdisc lock is held. Exploitation requires CONFIG_NET_SCH_FQ_PIE and namespace-local CAP_NET_ADMIN; the resulting lockup interrupts service without reported data access or modification.
Summary
What happened
Denial of service in affected Linux kernels allows local users to trigger a soft lockup through a crafted fq_pie queue discipline. fq_pie_change() accepts a user-supplied quantum of 1, letting a crafted size table inflate qdisc_pkt_len to about 2 GiB and force roughly 2^31 deficit-refill iterations while the qdisc lock is held. Exploitation requires CONFIG_NET_SCH_FQ_PIE and namespace-local CAP_NET_ADMIN; the resulting lockup interrupts service without reported data access or modification.
The record
- CVE
- CVE-2026-98013
- 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
- Sep 25, 2026CVE publishedPublication date reported by the CVE source.
- Sep 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=5.6
- Affected versionversion=ec97ecf1ebe485a17cd8395a5f35e6b80b57665a <4864f58c53eb47257d55e01f47d4a9f355f7f970
- Affected versionversion=ec97ecf1ebe485a17cd8395a5f35e6b80b57665a <6655b56e2801008566c594ef231f6c7b3f716c61
- Affected versionversion=ec97ecf1ebe485a17cd8395a5f35e6b80b57665a <c11e3a39807eb5a200445ae9082843ab86800415
- Affected versionversion=ec97ecf1ebe485a17cd8395a5f35e6b80b57665a <f90fe65b977e7aa9eb302230a09eb18f8c32ceaa
What conditions does exploitation require?
What is affected?
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.
Weakness, pattern, technique
Public exploit references
- fq_pie quantum and size-table reproductionproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Get started to see how Hinoki identifies affected software and validates exploitability in your environment.
Get started