What is CVE-2021-47538?

CVE-2021-47538 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, classified as a Memory Leak flaw (CWE-401), affecting Linux kernel versions from 4.19.82 onward and patched in 4.19.220, 5.4.164, 5.10.84 and others. CVE-2021-47538 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47538?

CVE-2021-47538 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-2021-47538?

Yes, CVE-2021-47538 has been patched. Fixed versions include 4.19.220, 5.4.164, 5.10.84 and others. If you are running Linux kernel 4.19.82 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-47538 actively exploited?

CVE-2021-47538 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-2021-47538

Medium

In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix rxrpc_local leak in rxrpc_lookup_peer() Need to call rxrpc_put_local() for peer candidate before kfree() as it holds a ref to rxrpc_local. [DH: v2: Changed to abstract the peer freeing code out into a function]

Package Linux Kernel

Published 2024-05-24

Last modified 2025-09-18

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

Weakness type

CWE-401

CVE-2021-47538 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 4.19.82, 5.3.9, 5.4 and later are affected. Fixed in 4.19.220, 5.4.164, 5.10.84, 5.15.7, 5.16 and their respective stable series.

Affected from

≥ 4.19.82 ≥ 5.3.9 ≥ 5.4

Fixed in

✓ 4.19.220 4.19.x ✓ 5.4.164 5.4.x ✓ 5.10.84 5.10.x ✓ 5.15.7 5.15.x ✓ 5.16

References

5 total

Kernel Git
https://git.kernel.org/stable/c/3e70e3a72d80b16094faccbe438cd53761c3503a

Patch
Kernel Git
https://git.kernel.org/stable/c/60f0b9c42cb80833a03ca57c1c8b078d716e71d1

Patch
Kernel Git
https://git.kernel.org/stable/c/913c24af2d13a3fd304462916ee98e298d56bdce

Patch
Kernel Git
https://git.kernel.org/stable/c/9469273e616ca8f1b6e3773c5019f21b4c8d828c

Patch
Kernel Git
https://git.kernel.org/stable/c/beacff50edbd6c9659a6f15fc7f6126909fade29

Patch

Details

CVE ID CVE-2021-47538

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2024-05-24

Modified 2025-09-18

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-47538?

CVE-2021-47538 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a Memory Leak flaw (CWE-401) . It affects Linux kernel versions from 4.19.82 onward and has been patched in 4.19.220, 5.4.164, 5.10.84 and others. CVE-2021-47538 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47538?

CVE-2021-47538 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-2021-47538?

Yes. CVE-2021-47538 has been patched. Fixed versions include 4.19.220, 5.4.164, 5.10.84 and others. If you are running Linux kernel 4.19.82 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-47538 actively exploited?

No. CVE-2021-47538 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.