Stack disclosure via uninitialized queue/stack helper output
Published Sep 17, 2026 · Updated Sep 17, 2026
Uninitialized output in Linux 6.6 BPF queue/stack helpers allows local users to read stack contents after failed lock acquisition. In kernel/bpf/queue_stack_maps.c, pop/peek helpers return -EBUSY without filling a buffer the verifier treats as initialized. Exploitation requires permission to run BPF programs and a failed lock acquisition; the disclosed consequence is stack-data exposure, not code execution.
Summary
What happened
Uninitialized output in Linux 6.6 BPF queue/stack helpers allows local users to read stack contents after failed lock acquisition. In kernel/bpf/queue_stack_maps.c, pop/peek helpers return -EBUSY without filling a buffer the verifier treats as initialized. Exploitation requires permission to run BPF programs and a failed lock acquisition; the disclosed consequence is stack-data exposure, not code execution.
The record
- CVE
- CVE-2026-92520
- Published
- Sep 17, 2026
- Updated
- Sep 17, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=232f0ba4d69263af5912e279fcc32fef2882b1dc
- Affected versionversion=388c9d3eefaea99828ee5000c693128a5b41ee7c
- Affected versionversion=40e34ea01748e5b8afdd40a172868be1e1ab0ede
- Affected versionversion=5.10.198 <5.11
- Affected versionversion=5.15.134 <5.16
- Affected versionversion=5.4.258 <5.5
- Affected versionversion=6.1.56 <6.2
- Affected versionversion=6.5.6 <6.6
- Affected versionversion=6.6
- Affected versionversion=a34a9f1a19afe9c60ca0ea61dfeee63a1c2baac8 <1534c4bff3aaca19c4c9a82f93e9b81f7c983de3
- Affected versionversion=a34a9f1a19afe9c60ca0ea61dfeee63a1c2baac8 <7ac6e1ae41a09f1dd4baeeff1d028ae49ee01232
- Affected versionversion=a34a9f1a19afe9c60ca0ea61dfeee63a1c2baac8 <e2396b8a562073787e627a5f483f1bc5c452fa6a
- Affected versionversion=acabf5df49aa3a4f9c96200102d893351b511a88
- Affected versionversion=e388671635acf470f0986d874389148fd234620b
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.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
No sourced classifications are available.
Public exploit references
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Technologies
Your stack
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