Service interruption via zero-bit nft_bitwise shift
Published May 27, 2026 · Updated May 27, 2026
Undefined behavior in affected Linux Kernel releases allows local users to interrupt system availability via a zero-bit nft_bitwise shift. The carry logic in net/netfilter/nft_bitwise.c subtracts a zero shift from the 32-bit word size, producing an undefined 32-bit shift while propagating an adjacent-word carry. Reachability requires local low-privileged access and the ability to submit an nftables rule containing a left or right shift expression.
Summary
What happened
Undefined behavior in affected Linux Kernel releases allows local users to interrupt system availability via a zero-bit nft_bitwise shift. The carry logic in net/netfilter/nft_bitwise.c subtracts a zero shift from the 32-bit word size, producing an undefined 32-bit shift while propagating an adjacent-word carry. Reachability requires local low-privileged access and the ability to submit an nftables rule containing a left or right shift expression.
The record
- CVE
- CVE-2026-46101
- Published
- May 27, 2026
- Updated
- May 27, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1499.004
- 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
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=5.6
- Affected versionversion=567d746b55bc66d3800c9ae91d50f0c5deb2fd93 <6f820139d16a4c9865a145d4a9cf9c92cc632c14
- Affected versionversion=567d746b55bc66d3800c9ae91d50f0c5deb2fd93 <bffef0acec9c3b837a785248a893137fb7f26c95
- Affected versionversion=567d746b55bc66d3800c9ae91d50f0c5deb2fd93 <ca24f1243ad1a4d12d6a23876bbbe3ed02099853
- Affected versionversion=567d746b55bc66d3800c9ae91d50f0c5deb2fd93 <f370205974f171a5868c13ff30d7642fed46e47b
- Affected versionversion=567d746b55bc66d3800c9ae91d50f0c5deb2fd93 <fe11e5c40817b84abaa5d83bfb6586d8412bfd07
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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