Kernel memory corruption via unchecked IPv4 header length
Published Aug 15, 2026 · Updated Aug 15, 2026
Out-of-bounds access in Linux kernel 6.19 allows remote attackers to corrupt kernel memory via malformed IPv4 tunnel headers. nf_flow_ip4_tunnel_proto() uses iph->ihl to compute the tunnel header size and parsing offset without first validating the field, so a short value drives later accesses outside the intended packet bounds. Reachability requires an administrator-configured nftables flowtable ingress hook; crafted packets can trigger kernel memory corruption, an information leak, or a crash.
Summary
What happened
Out-of-bounds access in Linux kernel 6.19 allows remote attackers to corrupt kernel memory via malformed IPv4 tunnel headers. nf_flow_ip4_tunnel_proto() uses iph->ihl to compute the tunnel header size and parsing offset without first validating the field, so a short value drives later accesses outside the intended packet bounds. Reachability requires an administrator-configured nftables flowtable ingress hook; crafted packets can trigger kernel memory corruption, an information leak, or a crash.
The record
- CVE
- CVE-2026-72417
- Published
- Aug 15, 2026
- Updated
- Aug 15, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-125, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 15, 2026CVE publishedPublication date reported by the CVE source.
- Aug 15, 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=6.19
- Affected versionversion=ab427db17885814069bae891834f20842f0ac3a4 <025a41e76b51fbc7b8eaa5bacbaa9621d00e6aa7
- Affected versionversion=ab427db17885814069bae891834f20842f0ac3a4 <84460b644329e25809b4a6d9279d6359d7fd8ebc
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What is affected?
Published CVSS scores
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Attacks
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Technologies
Your stack
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Your stack
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