Local privilege escalation via double-freed rbtree element
Published Feb 20, 2024 · Updated Aug 5, 2026
Use-after-free in Linux kernel 6.5 through 6.5.3 allows local users to gain kernel privileges via a crafted nftables batch. The __nft_rbtree_insert path synchronously frees a newly added element after its short timeout without excluding the current transaction, and abort processing destroys the same element again. CAP_NET_ADMIN obtained in user and network namespaces is sufficient; successful exploitation grants kernel memory control, while a failed attempt can panic the host.
Summary
What happened
Use-after-free in Linux kernel 6.5 through 6.5.3 allows local users to gain kernel privileges via a crafted nftables batch. The __nft_rbtree_insert path synchronously frees a newly added element after its short timeout without excluding the current transaction, and abort processing destroys the same element again. CAP_NET_ADMIN obtained in user and network namespaces is sufficient; successful exploitation grants kernel memory control, while a failed attempt can panic the host.
The record
- CVE
- CVE-2023-52433
- Published
- Feb 20, 2024
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-273, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 20, 2024CVE 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=146c76866795553dbc19998f36718d7986ad302b <c323ed65f66e5387ee0a73452118d49f1dae81b8
- Affected versionversion=479a2cf5259347d6a1f658b0f791d27a34908e91 <9af7dfb3c9d7985172a240f85e684c5cd33e29ce
- Affected versionversion=6.4.11 <6.5
- Affected versionversion=6.5
- Affected versionversion=c357648929c8dff891502349769aafb8f0452bc2 <03caf75da1059f0460666c826e9f50e13dfd0017
- Affected versionversion=cb4d00b563675ba8ff6ef94b077f58d816f68ba3 <9db9feb841f7449772f9393c16b9ef4536d8c127
- Affected versionversion=df650d6a4bf47248261b61ef6b174d7c54034d15 <9a8c544158f68f656d1734eb5ba00c4f817b76b1
- Affected versionversion=e4d71d6a9c7db93f7bf20c3a0f0659d63d7de681
- Affected versionversion=f6c383b8c31a93752a52697f8430a71dcbc46adf <2ee52ae94baabf7ee09cf2a8d854b990dac5d0e4
- Affected versionversion=f6c383b8c31a93752a52697f8430a71dcbc46adf <e3213ff99a355cda811b41e8dbb3472d13167a3a
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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
- Google kernelCTF CVE-2023-52433 mitigation exploitfunctional · demonstrated
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Technologies
Your stack
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Your stack
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