What is CVE-2026-64289?

CVE-2026-64289 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 6.8 onward and patched in 6.12.96, 6.18.39, 7.1.4 and others. CVE-2026-64289 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-64289?

CVE-2026-64289 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2026-64289?

Yes, CVE-2026-64289 has been patched. Fixed versions include 6.12.96, 6.18.39, 7.1.4 and others. If you are running Linux kernel 6.8 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-64289 actively exploited?

CVE-2026-64289 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-64289

Medium

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.

Package Linux Kernel

Published 2026-07-25

Last modified 2026-08-17

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected versions

Linux kernel versions 6.8 and later are affected. Fixed in 6.12.96, 6.18.39, 7.1.4, 7.2 and their respective stable series.

Affected from

≥ 6.8

Fixed in

✓ 6.12.96 6.12.x ✓ 6.18.39 6.18.x ✓ 7.1.4 7.1.x ✓ 7.2

References

4 total

Kernel Git
https://git.kernel.org/stable/c/2c6381d90898089287e0a358f06f89f6b4b389f2

Patch
Kernel Git
https://git.kernel.org/stable/c/32ca4aed2a66205b072fcfecabe220289a8149ff

Patch
Kernel Git
https://git.kernel.org/stable/c/4d70986002f2f3eaaed89124fb2522bded38b016

Patch
Kernel Git
https://git.kernel.org/stable/c/d2bd041e0efaf7d81789779b135279d18b33d6d5

Patch

Details

CVE ID CVE-2026-64289

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2026-07-25

Modified 2026-08-17

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-64289?

CVE-2026-64289 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 6.8 onward and has been patched in 6.12.96, 6.18.39, 7.1.4 and others. CVE-2026-64289 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-64289?

CVE-2026-64289 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2026-64289?

Yes. CVE-2026-64289 has been patched. Fixed versions include 6.12.96, 6.18.39, 7.1.4 and others. If you are running Linux kernel 6.8 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-64289 actively exploited?

No. CVE-2026-64289 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.