Kernel-level vulnerability in Linux netfilter/ipset affects widely deployed systems and can disrupt networking and hosts; high CVSS and kernel impact merit broad notification.
CVE-2026-72436
Linux kernel ipset RCU ordering bug can cause kernel memory corruption and DoS.
Is CVE-2026-72436 being exploited?
Not confirmed. CVE-2026-72436 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 0.71% probability of exploitation in the next 30 days.
How severe is CVE-2026-72436?
CVE-2026-72436 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-2026-72436?
Yes. A fix has been recorded for CVE-2026-72436. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-72436 affect?
CVE-2026-72436 affects Linux kernel (netfilter/ipset), Major distributions using affected kernels (Ubuntu, Debian, RHEL, SUSE, etc.). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-72436?
Apply vendor kernel updates/backports and reboot affected hosts immediately.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Memory-ordering bug in netfilter ipset can cause kernel memory corruption, remote DoS and potentially local privilege escalation via packet processing paths.
Immediate action required
- affected>= 18f84d41d34fa35d0d64bbaea01fe664553ecc06 and < c107233d2ff4fd7cef5d02f9124b99194957a710
- affected>= 18f84d41d34fa35d0d64bbaea01fe664553ecc06 and < 6329d3a9afe715fddda0460cfa46b496d61c2fe0
- affected>= 18f84d41d34fa35d0d64bbaea01fe664553ecc06 and < 7445fe965b7d8756070a40e80f8b73348ccda1d7
- affected>= 18f84d41d34fa35d0d64bbaea01fe664553ecc06 and < c4d257734e91bfcdc71d41843392dd6400b5bb1b
- affected>= 18f84d41d34fa35d0d64bbaea01fe664553ecc06 and < 3219d74e4536658c937fd878a327257b86ce80dd
- affected>= 18f84d41d34fa35d0d64bbaea01fe664553ecc06 and < e4b4984e28c16406ecb318444dea4a8bf47def3e
- affected4.2
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.