CVE-2026-74743: macvlan: inherit needed_headroom and needed_tailroom from lowerdev

highCVSS 7.1CVE-2026-74743

CSIRTS triage

vendor: Linux product: Linux kernel Denial of service

What: macvlan interface fails to inherit required buffer headroom and tailroom from the lower device, causing packet corruption or loss.
Who is affected: Systems using macvlan virtual interfaces over underlying physical or logical devices.
Urgency: High severity (CVSS 7.1) affecting network functionality and stability; patch required.
Action: Apply kernel patch for macvlan device inheritance of buffer requirements.

AI-assisted analysis generated from the source advisory — verify against the original.

⚡ Watch Linux kernel

Get an email when a new Linux kernel advisory drops — max one per day, one-click unsubscribe.

Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: high — CVSS 7.1
Published: 2026-08-11
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-74743

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-747430.52% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 42% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-74743	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

Recent advisories for macvlan

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

criticalCVE-2026-74743: In the Linux kernel, the following vulnerability has been resolved: macvlan: inherit needed_he…nvd · 2026-08-26
mediumCVE-2026-53013: macvlan: fix macvlan_get_size() not reserving space for IFLA_MACVLAN_BC_CUTOFFmsrc · 2026-06-09