Local privilege escalation via cross-table CHAIN_ID lookup
Published Jun 18, 2025 · Updated Aug 5, 2026
Use-after-free in Linux kernel nf_tables allows local users to execute code through a cross-table CHAIN_ID rule. The same-batch chain lookup accepts an ID from another table, leaving rule expressions tied to freed objects after their original table is deleted. A local process needs NETLINK_NETFILTER access and CAP_NET_ADMIN, obtainable in enabled user and network namespaces; processing the dangling expressions can disclose or overwrite kernel memory or crash the host.
Summary
What happened
Use-after-free in Linux kernel nf_tables allows local users to execute code through a cross-table CHAIN_ID rule. The same-batch chain lookup accepts an ID from another table, leaving rule expressions tied to freed objects after their original table is deleted. A local process needs NETLINK_NETFILTER access and CAP_NET_ADMIN, obtainable in enabled user and network namespaces; processing the dangling expressions can disclose or overwrite kernel memory or crash the host.
The record
- CVE
- CVE-2022-50212
- Published
- Jun 18, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 18, 2025CVE publishedPublication date reported by the CVE source.
- Aug 5, 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=5.9
- Affected versionversion=837830a4b439bfeb86c70b0115c280377c84714b <0f49613a213d918af790c1276f79da741968de11
- Affected versionversion=837830a4b439bfeb86c70b0115c280377c84714b <58e863f64ee3d0879297e5e53b646e4b91e59620
- Affected versionversion=837830a4b439bfeb86c70b0115c280377c84714b <91501513016903077f91033fa5d2aa26cac399b2
- Affected versionversion=837830a4b439bfeb86c70b0115c280377c84714b <95f466d22364a33d183509629d0879885b4f547e
- Affected versionversion=837830a4b439bfeb86c70b0115c280377c84714b <9e7dcb88ec8e85e4a8ad0ea494ea2f90f32d2583
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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