Crash via missing route state in direct transmit
Published Aug 15, 2026 · Updated Aug 15, 2026
Denial of service in Linux 6.19 allows local users to crash the system through netfilter direct transmit over an IPIP tunnel. Direct tunnel flow tuples omit a usable destination entry, so the transmit path cannot check packet headroom or set the IP fragmentation field and instead uses invalid route state. Reachability requires an IPIP tunnel using direct transmit, such as through a bridge device, and the documented consequence is a system crash.
Summary
What happened
Denial of service in Linux 6.19 allows local users to crash the system through netfilter direct transmit over an IPIP tunnel. Direct tunnel flow tuples omit a usable destination entry, so the transmit path cannot check packet headroom or set the IP fragmentation field and instead uses invalid route state. Reachability requires an IPIP tunnel using direct transmit, such as through a bridge device, and the documented consequence is a system crash.
The record
- CVE
- CVE-2026-72248
- Published
- Aug 15, 2026
- Updated
- Aug 15, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-824, T1499
- Attack vector
- local
- Privileges
- authenticated
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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=6.19
- Affected versionversion=d30301ba4b07ac92eb38353a111833b009003170 <0880c4ed122d0cddc9f29a2b28f055d1f24f0fca
- Affected versionversion=d30301ba4b07ac92eb38353a111833b009003170 <fa7395c02d95e51bad2952325d2d6503bfbad437
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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