Affects the Linux kernel (widely deployed). Misconfigured IOMMU/ACS when tboot is used can enable DMA-based kernel compromise, impacting servers, clouds and virtualized hosts.
CVE-2026-89448
Linux kernel VT-d IOMMU ACS misconfig can enable DMA-based kernel compromise
Is CVE-2026-89448 being exploited?
Not confirmed. CVE-2026-89448 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 0.14% probability of exploitation in the next 30 days.
How severe is CVE-2026-89448?
CVE-2026-89448 is rated Critical with a CVSS score of 9.3. 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-2026-89448?
Yes. A fix has been recorded for CVE-2026-89448. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-89448 affect?
CVE-2026-89448 affects Linux kernel (iommu/vt-d), tboot-enabled systems, Intel VT-d platforms, Virtualized hosts/guests. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-89448?
Install kernel update with ACS/tboot fix and reboot affected systems immediately.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Malicious PCIe device or VM can bypass ACS, perform arbitrary DMA to kernel/other VMs, enabling privilege escalation, RCE or VM escape.
Immediate action required
- affected>= 5d990b627537e59a3a2f039ff588a4750e9c1a6a and < aaeb81241e802c86be69394f72d49fde3f861fbb
- affected>= 5d990b627537e59a3a2f039ff588a4750e9c1a6a and < 45705a6bfdb283f7b3b509010fd617b72f942537
- affected>= 5d990b627537e59a3a2f039ff588a4750e9c1a6a and < 87bc611c6c98a41c00feb7b06b0c297dd141a2ae
- affected>= 5d990b627537e59a3a2f039ff588a4750e9c1a6a and < 607432b2618b61df81134be0ef2562b8300c1216
- affected2.6.33
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.