Memory disclosure via uninitialized stack-helper error buffers
Published Sep 17, 2026 · Updated Sep 17, 2026
Uninitialized buffers in Linux BPF stack helpers allow local users to read residual memory via helper error paths. In kernel/bpf/stackmap.c, __bpf_get_task_stack returns on failure without initializing the output buffer accepted by bpf_get_task_stack and bpf_get_task_stack_sleepable, leaving nondeterministic contents available to subsequent BPF operations. Reachability requires access to execute the affected BPF helpers; Amazon assesses disclosure requiring high privileges, while the upstream notice does not establish a crash or privilege-escalation consequence.
Summary
What happened
Uninitialized buffers in Linux BPF stack helpers allow local users to read residual memory via helper error paths. In kernel/bpf/stackmap.c, __bpf_get_task_stack returns on failure without initializing the output buffer accepted by bpf_get_task_stack and bpf_get_task_stack_sleepable, leaving nondeterministic contents available to subsequent BPF operations. Reachability requires access to execute the affected BPF helpers; Amazon assesses disclosure requiring high privileges, while the upstream notice does not establish a crash or privilege-escalation consequence.
The record
- CVE
- CVE-2026-90300
- Published
- Sep 17, 2026
- Updated
- Sep 17, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- admin
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=06ab134ce8ecfa5a69e850f88f81c8a4c3fa91df <f523359c4789bb0396d2d642464a6e2fd4f2299d
- Affected versionversion=06ab134ce8ecfa5a69e850f88f81c8a4c3fa91df <f5d242825ca417bb6afe35fde6e8880f97ca43fb
- Affected versionversion=5.10.30 <5.11
- Affected versionversion=5.10.96 <5.11
- Affected versionversion=5.11.14 <5.12
- Affected versionversion=5.12
- Affected versionversion=9c020a533eaae1c2d41a7e3835c4c818a9b4b656
- Affected versionversion=d921baabd96445ef9c9c9410ca06164359c8a1a5
- Affected versionversion=ff6bdc205fd0a83bd365405d4e31fb5905826996
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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Your stack
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