Out-of-bounds packet access via unsound verifier pruning
Published Oct 18, 2026 · Updated Oct 18, 2026
Verifier bypass in Linux 7.1 BPF allows local users to access packet memory outside verified bounds via crafted programs. The regsafe() function in kernel/bpf/states.c prunes program paths without preserving displacement between packet pointers sharing an ID, incorrectly transferring bounds-check guarantees. Exploitation requires permission to load a relevant BPF program; the published evidence establishes out-of-bounds packet access, not a demonstrated privilege-escalation outcome.
Summary
What happened
Verifier bypass in Linux 7.1 BPF allows local users to access packet memory outside verified bounds via crafted programs. The regsafe() function in kernel/bpf/states.c prunes program paths without preserving displacement between packet pointers sharing an ID, incorrectly transferring bounds-check guarantees. Exploitation requires permission to load a relevant BPF program; the published evidence establishes out-of-bounds packet access, not a demonstrated privilege-escalation outcome.
The record
- CVE
- CVE-2026-98627
- Published
- Oct 18, 2026
- Updated
- Oct 18, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Oct 18, 2026CVE publishedPublication date reported by the CVE source.
- Oct 18, 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=022ac075088366b62e130da5e1b200bc93a47191 <091b40845bd3cf96791171ca95113e9184ccb596
- Affected versionversion=022ac075088366b62e130da5e1b200bc93a47191 <fd16449a9b3b31a8f18944c2f0e29e4e218ca2cf
- Affected versionversion=7.1
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
No sourced classifications are available.
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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