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CVE · referencelatest edition

Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-64289MEDIUM
Linux Linux — iommufd: Set upper bounds on cache invalidation entry_num and entry_len
  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   L   L   L   N  U  N  N  H    5.5   .0015    5.2     —
AFFECTED
  Product  Versions                                    Fixed
  Linux    8c6eabae3807e048b9f17733af5e20500fbf858c –  —
  Linux    6.8 –                                       6.12.96
TIMELINE
  Jul 19  Reserved by Linux
  Jul 25  Published (CNA: Linux)
  Aug 17  ENRICHED — CVE-2026-64289 (Linux). Received CVSS 5.5 and CPE data from NVD.
CNA: Linux · CVSS v3.1 · 4 references · NVD status: Analyzed

Description

In the Linux kernel, the following vulnerability has been resolved: iommufd: Set upper bounds on cache invalidation entry_num and entry_len iommufd_hwpt_invalidate() takes a user-controlled entry_num and entry_len, each bounded only by U32_MAX. An entry_len beyond the kernel's struct size makes the copy helper verify the extra bytes are zero, scanning that excess in one uninterruptible pass; a multi-gigabyte value over zeroed user memory trips the soft-lockup watchdog. A large entry_num is the other half, driving the backend invalidation loop with no reschedule. The VT-d nested handler, for one, copies each entry and flushes caches per iteration, pinning the CPU on a non-preemptible kernel. Cap both in the ioctl. entry_len is held under PAGE_SIZE, above any request struct, and entry_num under 1 << 19, the order of a hardware invalidation queue and well beyond any real batch, bounding the per-call loop length.

Lifecycle

Complete event history — 3 events, chronological
DateEventDetail
July 19, 2026ReservedReserved by Linux
July 25, 2026PublishedPublished (CNA: Linux)
August 17, 2026ENRICHEDENRICHED — CVE-2026-64289 (Linux). Received CVSS 5.5 and CPE data from NVD.

Affected

Affected products and packages — 2 rows
VendorProduct / PackageEcosystemVersion introducedFixed
LinuxLinux8c6eabae3807e048b9f17733af5e20500fbf858c
LinuxLinux6.86.12.96

References (4)

Related

Authoritative record: CVE-2026-64289 at cve.org

Vendors: linux

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-64289 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.