Local privilege escalation via packet-header race
Published Aug 21, 2026 · Updated Aug 25, 2026
An out-of-bounds write in the Linux kernel allows local users to escalate privileges through concurrent AF_PACKET packet sends. packet_snd() and packet_sendmsg_spkt() read hard_header_len separately for allocation and header placement, so device reconfiguration can move skb->data before skb->head and copy attacker-controlled data outside the buffer. Exploitation requires CAP_NET_RAW and CAP_NET_ADMIN, obtainable inside paired user and network namespaces, and can also disclose kernel memory or crash the kernel.
Summary
What happened
An out-of-bounds write in the Linux kernel allows local users to escalate privileges through concurrent AF_PACKET packet sends. packet_snd() and packet_sendmsg_spkt() read hard_header_len separately for allocation and header placement, so device reconfiguration can move skb->data before skb->head and copy attacker-controlled data outside the buffer. Exploitation requires CAP_NET_RAW and CAP_NET_ADMIN, obtainable inside paired user and network namespaces, and can also disclose kernel memory or crash the kernel.
The record
- CVE
- CVE-2026-74582
- Published
- Aug 21, 2026
- Updated
- Aug 25, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-787, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 21, 2026CVE publishedPublication date reported by the CVE source.
- Aug 25, 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=01a658c1b9d4b5393c38d5a92d9112ab1425382a
- Affected versionversion=4.14.44 <4.15
- Affected versionversion=4.16.12 <4.17
- Affected versionversion=4.17
- Affected versionversion=4.4.133 <4.5
- Affected versionversion=4.9.103 <4.10
- Affected versionversion=6190cce26e40bf71c4d375b21eea74bb07b6a0f3
- Affected versionversion=8809ae6747e760e6f1d2453ceb08c9bcc4939766
- Affected versionversion=b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba <03390aa32e669cc4ecd7d34108e2e1afc13d689d
- Affected versionversion=b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba <5bb10753d428aadfc356a2bfe9acea09c82a62ec
- Affected versionversion=b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba <9052756290962ffb9a661bcf319e92dedaaedfed
- Affected versionversion=b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba <91f041451f967cd87ed722a8f43c0b767a64f1a0
- Affected versionversion=b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba <b06b6fce6d7deaf7238e09b48ce3b1125ff41acd
- Affected versionversion=d9fb8cc230b2a4757e9fe4f81468f81212d4deaa
What conditions does exploitation require?
What is affected?
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.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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