Local privilege escalation via broken BPF register links
Published May 27, 2026 · Updated May 27, 2026
Out-of-bounds access in the Linux kernel BPF verifier allows local users to gain kernel privileges via crafted BPF code. The sync_linked_regs() function copies a BPF_ADD_CONST-derived register ID while propagating bounds, breaking register links and leaving stale bounds that let unsafe accesses pass verification. A local low-privilege user must be able to load unprivileged BPF programs; successful exploitation permits kernel memory reads or writes, privilege escalation, or a kernel crash.
Summary
What happened
Out-of-bounds access in the Linux kernel BPF verifier allows local users to gain kernel privileges via crafted BPF code. The sync_linked_regs() function copies a BPF_ADD_CONST-derived register ID while propagating bounds, breaking register links and leaving stale bounds that let unsafe accesses pass verification. A local low-privilege user must be able to load unprivileged BPF programs; successful exploitation permits kernel memory reads or writes, privilege escalation, or a kernel crash.
The record
- CVE
- CVE-2026-45933
- Published
- May 27, 2026
- Updated
- May 27, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 27, 2026CVE publishedPublication date reported by the CVE source.
- May 27, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=6.11
- Affected versionversion=98d7ca374ba4b39e7535613d40e159f09ca14da2 <58059335e46537de682db84984f7716c813208c4
- Affected versionversion=98d7ca374ba4b39e7535613d40e159f09ca14da2 <65d114b5270b62aefb820ecd6c3b7caeea8f895d
- Affected versionversion=98d7ca374ba4b39e7535613d40e159f09ca14da2 <92a8cb1806adefb263cf096eab6705705cf7eee1
- Affected versionversion=98d7ca374ba4b39e7535613d40e159f09ca14da2 <af9e89d8dd39530c8bd14c33ddf6b502df1071b6
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.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo