Host crash via undersized IPv4 header length
Published Jul 19, 2026 · Updated Jul 19, 2026
Out-of-bounds access in affected Linux Kernel releases allows local users to crash the host through a malformed IP_HDRINCL packet. raw_send_hdrinc() accepts a caller-supplied IPv4 header whose ihl is below five, and ah_output() converts the resulting negative length to size_t before memcpy(). Triggering the reproduced panic requires CAP_NET_RAW, a real network device, and a matching outbound xfrm AH policy; a user and network namespace can supply the required capabilities.
Summary
What happened
Out-of-bounds access in affected Linux Kernel releases allows local users to crash the host through a malformed IP_HDRINCL packet. raw_send_hdrinc() accepts a caller-supplied IPv4 header whose ihl is below five, and ah_output() converts the resulting negative length to size_t before memcpy(). Triggering the reproduced panic requires CAP_NET_RAW, a real network device, and a matching outbound xfrm AH policy; a user and network namespace can supply the required capabilities.
The record
- CVE
- CVE-2026-64114
- Published
- Jul 19, 2026
- Updated
- Jul 19, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-125, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 19, 2026CVE publishedPublication date reported by the CVE source.
- Jul 19, 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1065b9efa4126df559b03a849c139ecfae92cd25
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <145e9afa5b905229b4788bb72c3255f5a5f77508
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3c5411fa4944ed99af3d9d1de750ea8169b6dac9
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5a564f737ec54d63e8ee221d3ff396d07586d464
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7725cd3b471740fd23d25ed1da722c671fb2a5d3
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <915fab69823a14c170dbaa3b41978768e0fe62fc
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <bbe0be67de296176e7243c76e3d9f02f6ae9ff0b
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <bc20dbd48c26e743f7e0845020c11ed2ce8b15ee
- Affected versionversion=2.6.12
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.
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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