What is CVE-2021-47649?

CVE-2021-47649 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 4.20 onward and patched in 5.4.189, 5.10.110, 5.15.33 and others. CVE-2021-47649 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47649?

CVE-2021-47649 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-2021-47649?

Yes, CVE-2021-47649 has been patched. Fixed versions include 5.4.189, 5.10.110, 5.15.33 and others. If you are running Linux kernel 4.20 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-47649 actively exploited?

CVE-2021-47649 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2021-47649

Medium

In the Linux kernel, the following vulnerability has been resolved: udmabuf: validate ubuf->pagecount Syzbot has reported GPF in sg_alloc_append_table_from_pages(). The problem was in ubuf->pages == ZERO_PTR. ubuf->pagecount is calculated from arguments passed from user-space. If user creates udmabuf with list.size == 0 then ubuf->pagecount will be also equal to zero; it causes kmalloc_array() to return ZERO_PTR. Fix it by validating ubuf->pagecount before passing it to kmalloc_array().

Package Linux Kernel

Published 2025-02-26

Last modified 2025-10-14

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 4.20 and later are affected. Fixed in 5.4.189, 5.10.110, 5.15.33, 5.16.19, 5.17.2, 5.18 and their respective stable series.

Affected from

≥ 4.20

Fixed in

✓ 5.4.189 5.4.x ✓ 5.10.110 5.10.x ✓ 5.15.33 5.15.x ✓ 5.16.19 5.16.x ✓ 5.17.2 5.17.x ✓ 5.18

References

The following references provide additional information about CVE-2021-47649 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/2b6dd600dd72573c23ea180b5b0b2f1813405882
Patch
Kernel patch commit
https://git.kernel.org/stable/c/5d50f851dd307c07ca5591297093f19967c834a9
Patch
Kernel patch commit
https://git.kernel.org/stable/c/811b667cefbea9cb7511a874b169d6a92907137e
Patch

6 patch commits total View all on NVD

Details

CVE ID CVE-2021-47649

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2025-02-26

Modified 2025-10-14

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-47649?

CVE-2021-47649 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 4.20 onward and has been patched in 5.4.189, 5.10.110, 5.15.33 and others. CVE-2021-47649 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47649?

CVE-2021-47649 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-2021-47649?

Yes — CVE-2021-47649 has been patched. Fixed versions include 5.4.189, 5.10.110, 5.15.33 and others. If you are running Linux kernel 4.20 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-47649 actively exploited?

No — CVE-2021-47649 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.