What is CVE-2021-47655?

CVE-2021-47655 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 5.16 onward and patched in 5.16.19, 5.17.2 and 5.18. CVE-2021-47655 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47655?

CVE-2021-47655 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-2021-47655?

Yes, CVE-2021-47655 has been patched. Fixed versions include 5.16.19, 5.17.2 and 5.18. If you are running Linux kernel 5.16 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-47655 actively exploited?

CVE-2021-47655 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-2021-47655

Medium

In the Linux kernel, the following vulnerability has been resolved: media: venus: vdec: fixed possible memory leak issue The venus_helper_alloc_dpb_bufs() implementation allows an early return on an error path when checking the id from ida_alloc_min() which would not release the earlier buffer allocation. Move the direct kfree() from the error checking of dma_alloc_attrs() to the common fail path to ensure that allocations are released on all error paths in this function. Addresses-Coverity: 1494120 ("Resource leak")

Package Linux Kernel

Published 2025-02-26

Last modified 2025-10-01

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-2021-47655 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 5.16 and later are affected. Fixed in 5.16.19, 5.17.2, 5.18 and their respective stable series.

Affected from

≥ 5.16

Fixed in

✓ 5.16.19 5.16.x ✓ 5.17.2 5.17.x ✓ 5.18

References

The following references provide additional information about CVE-2021-47655 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Kernel patch commit
https://git.kernel.org/stable/c/55bccafc246b2e64763a155ec454470c07a54a6e
Patch
Kernel patch commit
https://git.kernel.org/stable/c/5cedfe8aaf1875a5305897107b7f298db4260019
Patch
Kernel patch commit
https://git.kernel.org/stable/c/5f89d05ba93df9c2cdfe493843f93288e55e99eb
Patch

4 patch commits total View all on NVD

Details

CVE ID CVE-2021-47655

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2025-02-26

Modified 2025-10-01

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-47655?

CVE-2021-47655 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 5.16 onward and has been patched in 5.16.19, 5.17.2 and 5.18. CVE-2021-47655 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47655?

CVE-2021-47655 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-2021-47655?

Yes — CVE-2021-47655 has been patched. Fixed versions include 5.16.19, 5.17.2 and 5.18. If you are running Linux kernel 5.16 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-47655 actively exploited?

No — CVE-2021-47655 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
What is Memory Leak (CWE-401)?

The product does not release memory after use, causing gradual resource exhaustion. View CWE-401 on MITRE CWE →