Kernel memory corruption via unlocked conntrack access
Published May 6, 2026 · Updated May 6, 2026
Use-after-free in Linux Kernel netfilter ctnetlink allows local users to read or modify kernel memory or crash the host through expectation operations. Expectation lookup, deletion, and IPEXP_NEW event paths dereference exp->master without holding nf_conntrack_expect_lock, allowing the master conntrack to be freed concurrently. Exploitation requires local access and CAP_NET_ADMIN in the target network namespace; no victim action is required.
Summary
What happened
Use-after-free in Linux Kernel netfilter ctnetlink allows local users to read or modify kernel memory or crash the host through expectation operations. Expectation lookup, deletion, and IPEXP_NEW event paths dereference exp->master without holding nf_conntrack_expect_lock, allowing the master conntrack to be freed concurrently. Exploitation requires local access and CAP_NET_ADMIN in the target network namespace; no victim action is required.
The record
- CVE
- CVE-2026-43116
- Published
- May 6, 2026
- Updated
- May 6, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-362
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- May 6, 2026CVE publishedPublication date reported by the CVE source.
- May 6, 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <497f99b26fffdc5635706d1b4811f1ed8ee21a5b
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <bffcaad9afdfe45d7fc777397d3b83c1e3ebffe5
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f338ced0473849c9f6ed0b77ca99f1aab5826787
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What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
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Technologies
Your stack
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Your stack
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