Linux kernel IOMMU bug undermines DMA isolation on ARM SMMUv3, impacting virtualization and many Linux deployments; high risk to cloud/host security.
CVE-2026-74573
Linux arm-smmu v3 IOMMU bug can break DMA isolation and cause OOB reads.
Is CVE-2026-74573 being exploited?
Not confirmed. CVE-2026-74573 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 0.13% probability of exploitation in the next 30 days.
How severe is CVE-2026-74573?
CVE-2026-74573 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-2026-74573?
Yes. A fix has been recorded for CVE-2026-74573. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-74573 affect?
CVE-2026-74573 affects Linux kernel (arm-smmu v3 / iommufd), ARM SMMUv3 platforms, Virtualization hosts/guests using IOMMU, Cloud ARM instances (e.g., Graviton-like). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-74573?
Apply vendor/kernel patches for arm-smmu v3/iommufd immediately; restrict untrusted device access until patched.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
IOMMU stream mapping flaw can bypass DMA isolation, enabling cross-VM data leakage, kernel OOB read or DoS and potential host/VM compromise.
Immediate action required
- affected>= d68beb276ba26cec47350a6d468e967673ee0c56 and < 3808bab5d95ae79e333e11f6a73d178e084c645d
- affected>= d68beb276ba26cec47350a6d468e967673ee0c56 and < 0acbc621341aca4eb94d9c2f43e1ab273ff088f0
- affected>= d68beb276ba26cec47350a6d468e967673ee0c56 and < c3b8ee84a965058b41275069d4696f37a8b14bf6
- affected6.13
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.