Integrity bypass via mutable BPF map hash
Published May 27, 2026 · Updated May 27, 2026
A BPF TOCTOU flaw in Linux Kernel 6.18 through 6.18.13 and 6.19 through 6.19.3 allows local users to bypass map-integrity checks. The bpf_map_get_info_by_fd path caches a hash before the map is frozen, so userspace can alter map contents while the stale digest remains trusted. Exploitation requires local BPF map access and a trusted loader that later accepts the cached hash, allowing altered BPF data to pass integrity verification.
Summary
What happened
A BPF TOCTOU flaw in Linux Kernel 6.18 through 6.18.13 and 6.19 through 6.19.3 allows local users to bypass map-integrity checks. The bpf_map_get_info_by_fd path caches a hash before the map is frozen, so userspace can alter map contents while the stale digest remains trusted. Exploitation requires local BPF map access and a trusted loader that later accepts the cached hash, allowing altered BPF data to pass integrity verification.
The record
- CVE
- CVE-2026-45927
- Published
- May 27, 2026
- Updated
- May 27, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-367
- 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=6.18
- Affected versionversion=ea2e6467ac36bf3d785defc89e58269b15d182f7 <7752d36343862323bbeea4ce3adf0ec2ed86e122
- Affected versionversion=ea2e6467ac36bf3d785defc89e58269b15d182f7 <a2c86aa621c22f2a7e26c654f936d65cfff0aa91
- Affected versionversion=ea2e6467ac36bf3d785defc89e58269b15d182f7 <f415e114b58fe02c41191e47f24bdabb438daf72
What conditions does exploitation require?
What is affected?
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