What is CVE-2026-53187?

CVE-2026-53187 is a High severity Linux kernel vulnerability with a CVSS score of 7.1 out of 10, classified as a Out-of-bounds Write flaw (CWE-787), affecting Linux kernel versions from 6.17 onward and patched in 6.18.36, 7.0.13 and 7.1. CVE-2026-53187 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-53187?

CVE-2026-53187 has a CVSS score of 7.1 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H.

Is there a patch available for CVE-2026-53187?

Yes, CVE-2026-53187 has been patched. Fixed versions include 6.18.36, 7.0.13 and 7.1. If you are running Linux kernel 6.17 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-53187 actively exploited?

CVE-2026-53187 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Out-of-bounds Write (CWE-787)?

The product writes data past the end or before the beginning of the intended buffer. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/787.html

CVE-2026-53187

High

In the Linux kernel, the following vulnerability has been resolved: RDMA/core: Validate cpu_id against nr_cpu_ids in DMAH alloc The cpu_id attribute supplied by user space through UVERBS_ATTR_ALLOC_DMAH_CPU_ID is passed directly to cpumask_test_cpu() without first verifying that the value is within the valid CPU range. Passing such untrusted data to cpumask_test_cpu() may lead to an out-of-bounds read of the underlying cpumask bitmap: the helper expands to a test_bit() that indexes the bitmap by cpu_id / BITS_PER_LONG with no bound check. In addition, on kernels built with CONFIG_DEBUG_PER_CPU_MAPS it trips the WARN_ON_ONCE() in cpumask_check(); combined with panic_on_warn this turns a bad user input into a machine reboot. Reject any cpu_id that is not smaller than nr_cpu_ids with -EINVAL before it is used. Reported by Smatch.

Package Linux Kernel

Published 2026-06-25

Last modified 2026-07-06

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.1

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

High

Vector string

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

Weakness type

CWE-787

CVE-2026-53187 is a Out-of-bounds Write vulnerability

What is Out-of-bounds Write?

The product writes data past the end or before the beginning of the intended buffer. Learn more on MITRE CWE

Affected versions

Linux kernel versions 6.17 and later are affected. Fixed in 6.18.36, 7.0.13, 7.1 and their respective stable series.

Affected from

≥ 6.17

Fixed in

✓ 6.18.36 6.18.x ✓ 7.0.13 7.0.x ✓ 7.1

References

3 total

Kernel Git
https://git.kernel.org/stable/c/0efbb6b54ff56300867027d8e0800d0e32226a20

Patch
Kernel Git
https://git.kernel.org/stable/c/323c98a4ff06aa28114f2bf658fb43eb3b536bbc

Patch
Kernel Git
https://git.kernel.org/stable/c/bd5e818be7964c1689fba2dad9e6bd3a827fee74

Patch

Details

CVE ID CVE-2026-53187

Severity High

CVSS score 7.1 / 10

CVSS version 3.1

Published 2026-06-25

Modified 2026-07-06

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-53187?

CVE-2026-53187 is a High severity Linux kernel vulnerability with a CVSS score of 7.1 out of 10 , classified as an Out-of-bounds Write flaw (CWE-787) . It affects Linux kernel versions from 6.17 onward and has been patched in 6.18.36, 7.0.13 and 7.1. CVE-2026-53187 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-53187?

CVE-2026-53187 has a CVSS score of 7.1 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H.
Is there a patch available for CVE-2026-53187?

Yes. CVE-2026-53187 has been patched. Fixed versions include 6.18.36, 7.0.13 and 7.1. If you are running Linux kernel 6.17 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-53187 actively exploited?

No. CVE-2026-53187 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.