What is CVE-2026-53396?

CVE-2026-53396 is a High severity Linux kernel vulnerability with a CVSS score of 7.1 out of 10, classified as a Memory Leak flaw (CWE-401), affecting Linux kernel versions from 6.19 onward and patched in 7.1.3 and 7.2. CVE-2026-53396 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-53396?

CVE-2026-53396 has a CVSS score of 7.1 out of 10, rated High severity. The vector string is CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H.

Is there a patch available for CVE-2026-53396?

Yes, CVE-2026-53396 has been patched. Fixed versions include 7.1.3 and 7.2. If you are running Linux kernel 6.19 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-53396 actively exploited?

CVE-2026-53396 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Memory Leak (CWE-401)?

The product does not release memory after use, causing gradual resource exhaustion. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/401.html

CVE-2026-53396

High

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix posix_acl leak and ignored error in nfsd4_create_file nfsd4_create_file() has two bugs in its ACL handling: The return value of nfsd4_acl_to_attr() is silently discarded. When the NFSv4-to-POSIX ACL conversion fails (e.g., -EINVAL for unsupported ACE types), the file is created without any ACL and the client receives NFS4_OK. This violates RFC 7530/8881 which require the server to reject unsupported attributes on CREATE. When start_creating() fails after ACL attributes have been populated in attrs (either via nfsd4_acl_to_attr or via ownership transfer from open->op_dpacl/op_pacl), the function jumps to out_write which skips nfsd_attrs_free(). The posix_acl allocations are leaked. A client can trigger this repeatedly with OPEN(CREATE), ACL attributes, and an invalid filename (e.g., longer than NAME_MAX). Fix both by capturing the nfsd4_acl_to_attr() return value and by changing the early error paths to jump to out instead of out_write. Initialize child to ERR_PTR(-EINVAL) so that end_creating() is safe to call even if start_creating() was never reached.

Package Linux Kernel

Published 2026-07-19

Last modified 2026-08-17

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.1

out of 10

High

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

High

Vector string

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

Weakness type

CWE-401

CVE-2026-53396 is a Memory Leak vulnerability

What is Memory Leak?

The product does not release memory after use, causing gradual resource exhaustion. Learn more on MITRE CWE

Affected versions

Linux kernel versions 6.19 and later are affected. Fixed in 7.1.3, 7.2 and their respective stable series.

Affected from

≥ 6.19

Fixed in

✓ 7.1.3 7.1.x ✓ 7.2

References

2 total

Kernel Git
https://git.kernel.org/stable/c/18cf006a08babec0bbac2a3784f8f28e56e47490

Patch
Kernel Git
https://git.kernel.org/stable/c/24c975bbdd564d7d0ad90294bfa69729830345de

Patch

Details

CVE ID CVE-2026-53396

Severity High

CVSS score 7.1 / 10

CVSS version 3.1

Published 2026-07-19

Modified 2026-08-17

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-53396?

CVE-2026-53396 is a High severity Linux kernel vulnerability with a CVSS score of 7.1 out of 10 , classified as a Memory Leak flaw (CWE-401) . It affects Linux kernel versions from 6.19 onward and has been patched in 7.1.3 and 7.2. CVE-2026-53396 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-53396?

CVE-2026-53396 has a CVSS score of 7.1 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H.
Is there a patch available for CVE-2026-53396?

Yes. CVE-2026-53396 has been patched. Fixed versions include 7.1.3 and 7.2. If you are running Linux kernel 6.19 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-53396 actively exploited?

No. CVE-2026-53396 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.