Linux kernel is ubiquitous; kernel networking vuln can disrupt infrastructure and enable remote crash or RCE across many deployments.
CVE-2026-72417
Linux netfilter flowtable OOB via malformed IPv4 headers — remote crash/RCE risk
Is CVE-2026-72417 being exploited?
Not confirmed. CVE-2026-72417 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.55% probability of exploitation in the next 30 days.
How severe is CVE-2026-72417?
CVE-2026-72417 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-72417?
Yes. A fix has been recorded for CVE-2026-72417. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-72417 affect?
CVE-2026-72417 affects Linux kernel (netfilter nf_flow_ip4_tunnel_proto), IPv4 tunnel/IPIP packet processing, Common distro kernels (Debian/Ubuntu/RHEL/SUSE). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-72417?
Apply vendor/kernel updates ASAP; block or inspect IPIP/tunnel traffic until patched.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Crafted IPv4 tunnel/IPIP headers can trigger kernel out-of-bounds access, causing remote DoS and possibly remote code execution/privilege escalation.
Immediate action required
- affected>= ab427db17885814069bae891834f20842f0ac3a4 and < 025a41e76b51fbc7b8eaa5bacbaa9621d00e6aa7
- affected>= ab427db17885814069bae891834f20842f0ac3a4 and < 84460b644329e25809b4a6d9279d6359d7fd8ebc
- affected6.19
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.