Local privilege escalation via teql dangling pointer
Published Feb 4, 2026 · Updated Feb 4, 2026
Use-after-free in the Linux Kernel networking scheduler allows local users to gain kernel-level privileges through a crafted qdisc tree. When teql is nested beneath QFQ, teql enqueue leaves the parent-visible queue length at zero because peek returns NULL, so a class update frees aggregate pointers that a delayed packet later dereferences. Local low-privileged access and creation of the crafted scheduler configuration are required; successful exploitation grants control in kernel context and can crash the host.
Summary
What happened
Use-after-free in the Linux Kernel networking scheduler allows local users to gain kernel-level privileges through a crafted qdisc tree. When teql is nested beneath QFQ, teql enqueue leaves the parent-visible queue length at zero because peek returns NULL, so a class update frees aggregate pointers that a delayed packet later dereferences. Local low-privileged access and creation of the crafted scheduler configuration are required; successful exploitation grants control in kernel context and can crash the host.
The record
- CVE
- CVE-2026-23074
- Published
- Feb 4, 2026
- Updated
- Feb 4, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-416, CWE-825, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 4, 2026CVE publishedPublication date reported by the CVE source.
- Feb 4, 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.
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <0686bedfed34155520f3f735cbf3210cb9044380
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <16ed73c1282d376b956bff23e5139add061767ba
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4c7e8aa71c9232cba84c289b4b56cba80b280841
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <50da4b9d07a7a463e2cfb738f3ad4cff6b2c9c3b
- Affected versionversion=2.6.12
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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