Memory-limit bypass via uncharged classifier allocations
Published Sep 17, 2026 · Updated Sep 17, 2026
Memory-accounting bypass in Linux Kernel traffic-control classifiers allows local users to pin kernel memory via repeated filter creation. The classifier *_change() paths and tcf_exts_init_ex() allocate filter data without __GFP_ACCOUNT, excluding those allocations from memory-cgroup charges. Exploitation requires enabled scheduling, classifier, action, memory-cgroup, and namespace support plus user/network namespace access or CAP_NET_ADMIN; the documented consequence is kernel-memory consumption outside cgroup limits, not a specified crash or reboot.
Summary
What happened
Memory-accounting bypass in Linux Kernel traffic-control classifiers allows local users to pin kernel memory via repeated filter creation. The classifier *_change() paths and tcf_exts_init_ex() allocate filter data without __GFP_ACCOUNT, excluding those allocations from memory-cgroup charges. Exploitation requires enabled scheduling, classifier, action, memory-cgroup, and namespace support plus user/network namespace access or CAP_NET_ADMIN; the documented consequence is kernel-memory consumption outside cgroup limits, not a specified crash or reboot.
The record
- CVE
- CVE-2026-90099
- Published
- Sep 17, 2026
- Updated
- Sep 17, 2026
- Vendor
- Linux Foundation
- Product
- Linux Kernel
- Classifications
- T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 17, 2026CVE publishedPublication date reported by the CVE source.
- Sep 17, 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?
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- Affected versionversion=0da974f4f303a6842516b764507e3c0a03f41e5a <18c68c8f3d3ff0a4def1391021b439c4333a6c71
- Affected versionversion=0da974f4f303a6842516b764507e3c0a03f41e5a <1beb81947eb486716af80db7a584f9e9fef7e003
- Affected versionversion=2.6.18
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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