Linux kernel is core infrastructure used everywhere; a CVSS 10.0 kernel memory corruption can cause widescale host crashes or kernel RCE, impacting enterprise servers and cloud providers.
CVE-2026-74705
Linux kernel UDP tunnel use-after-free allows kernel memory corruption
Is CVE-2026-74705 being exploited?
Not confirmed. CVE-2026-74705 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 0.50% probability of exploitation in the next 30 days.
How severe is CVE-2026-74705?
CVE-2026-74705 is rated Critical. 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-2026-74705?
Yes. A fix has been recorded for CVE-2026-74705. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-74705 affect?
CVE-2026-74705 affects Linux kernel (udp tunnel segmentation code), Linux distributions: Ubuntu, Debian, RHEL, CentOS, SUSE (and derivatives), Cloud hosts, VMs, and appliances processing UDP tunnels (VXLAN/Geneve). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-74705?
Install vendor kernel updates immediately; block/untrust UDP tunnels and filter tunnel traffic.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote crafted UDP tunnel packets can trigger a kernel use-after-free, enabling DoS and potential kernel-level RCE or privilege escalation.
Immediate action required
- affected>= dbef491ebe7f3a4fb1b9111878b86a426fd540b7 and < 6a733a38b983d8c2e222f13968209010cf44de87
- affected>= dbef491ebe7f3a4fb1b9111878b86a426fd540b7 and < 19d89b13a43640b2da2f277ee462d919d988cb6f
- affected>= dbef491ebe7f3a4fb1b9111878b86a426fd540b7 and < b3df61bb745eb5201eac22679a2839d4ccbf3442
- affected>= dbef491ebe7f3a4fb1b9111878b86a426fd540b7 and < 1ae134c012e10384cdac420b5cc6e0615cde0b55
- affected>= dbef491ebe7f3a4fb1b9111878b86a426fd540b7 and < 5161e67c561c4f28a5d9335a6e859b02511de92b
- affected>= dbef491ebe7f3a4fb1b9111878b86a426fd540b7 and < 64d322c288577793eedd352b96ef75234ed380fe
- affected>= dbef491ebe7f3a4fb1b9111878b86a426fd540b7 and < 588d4a6795d99d080f74ef0b5f391ea8c453ae5d
- affected>= dbef491ebe7f3a4fb1b9111878b86a426fd540b7 and < d0f86fb36eb260abd10007b62c9dcc1028e03e61
- affected4.6
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.