Service interruption via mlx5e fragment undercount
Published May 8, 2026 · Updated May 8, 2026
Incorrect fragment accounting in affected Linux Kernel releases allows remote attackers to interrupt service through XDP multi-buffer traffic. The mlx5e legacy receive-queue path in en_rx.c fails to count an original fragment after bpf_xdp_pull_data() or bpf_xdp_adjust_tail() changes the buffer layout, producing a negative pp_ref_count during page release. Exposure requires an mlx5 legacy receive queue and an XDP multi-buffer program using those helpers; the documented consequence is a kernel warning and service interruption.
Summary
What happened
Incorrect fragment accounting in affected Linux Kernel releases allows remote attackers to interrupt service through XDP multi-buffer traffic. The mlx5e legacy receive-queue path in en_rx.c fails to count an original fragment after bpf_xdp_pull_data() or bpf_xdp_adjust_tail() changes the buffer layout, producing a negative pp_ref_count during page release. Exposure requires an mlx5 legacy receive queue and an XDP multi-buffer program using those helpers; the documented consequence is a kernel warning and service interruption.
The record
- CVE
- CVE-2026-43464
- Published
- May 8, 2026
- Updated
- May 8, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 8, 2026CVE publishedPublication date reported by the CVE source.
- May 8, 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?
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- Affected versionversion=0049fd63881505566824e88cfa624638f921c808
- Affected versionversion=6.18
- Affected versionversion=72328f25755ee966724f46e3a0e8e59bef2091ba
- Affected versionversion=afd5ba577c10639f62e8120df67dc70ea4b61176 <03cb50e5b74fce8bf6d92b860371b66253cf0f8d
- Affected versionversion=afd5ba577c10639f62e8120df67dc70ea4b61176 <a6413e6f6c9d9bb9833324cb3753582f7bc0f2fa
- Affected versionversion=afd5ba577c10639f62e8120df67dc70ea4b61176 <c74557495efb4bd0adefdfc8678ecdbc82a06da3
- Affected versionversion=d969645b9b7810289bf3c353ea06957373756b8e
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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