Affects the Linux kernel's nftables used widely across organizations; can bypass firewall policy and expose networks—actionable and broadly impactful.
CVE-2026-72320
Linux nftables bug mis-handles inverted lookups, enabling firewall rule bypass.
Is CVE-2026-72320 being exploited?
Not confirmed. CVE-2026-72320 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 0.52% probability of exploitation in the next 30 days.
How severe is CVE-2026-72320?
CVE-2026-72320 is rated Critical with a CVSS score of 9.1. 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-2026-72320?
Yes. A fix has been recorded for CVE-2026-72320. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-72320 affect?
CVE-2026-72320 affects Linux kernel (netfilter/nftables), Linux distributions using nftables (Debian/Ubuntu/Red Hat/SUSE, etc.). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-72320?
Apply vendor kernel updates or nftables backport patch immediately.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote attackers can craft packets to make nftables wrongly match/skip the catchall, allowing firewall rule bypass or unintended traffic acceptance.
Immediate action required
- affected>= aaa31047a6d25da0fa101da1ed544e1247949b40 and < 0ab8880865f9678eb6174e72c1fc4712e44c745c
- affected>= aaa31047a6d25da0fa101da1ed544e1247949b40 and < 238c612357b5a25f03eacf356f95034f8551f218
- affected>= aaa31047a6d25da0fa101da1ed544e1247949b40 and < ef0c7d4b04a0e6ad175323c24bc84e11470dd79d
- affected>= aaa31047a6d25da0fa101da1ed544e1247949b40 and < e6107a4c74b54cb33e3bce162a63048ae5a6b198
- affected5.13
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.