What is CVE-2021-47577?

CVE-2021-47577 is a Medium severity Linux kernel vulnerability with a CVSS score of 4.7 out of 10, classified as a Race Condition flaw (CWE-362), affecting Linux kernel versions from 5.13 onward and patched in 5.15.11 and 5.16. CVE-2021-47577 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47577?

CVE-2021-47577 has a CVSS score of 4.7 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2021-47577?

Yes, CVE-2021-47577 has been patched. Fixed versions include 5.15.11 and 5.16. If you are running Linux kernel 5.13 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-47577 actively exploited?

CVE-2021-47577 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Race Condition (CWE-362)?

The product contains a code sequence that can run concurrently with other code, creating unexpected states. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/362.html

CVE-2021-47577

Medium

In the Linux kernel, the following vulnerability has been resolved: io-wq: check for wq exit after adding new worker task_work We check IO_WQ_BIT_EXIT before attempting to create a new worker, and wq exit cancels pending work if we have any. But it's possible to have a race between the two, where creation checks exit finding it not set, but we're in the process of exiting. The exit side will cancel pending creation task_work, but there's a gap where we add task_work after we've canceled existing creations at exit time. Fix this by checking the EXIT bit post adding the creation task_work. If it's set, run the same cancelation that exit does.

Package Linux Kernel

Published 2024-06-19

Last modified 2025-09-29

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

4.7

out of 10

Medium

Attack Vector

Local

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

High

Vector string

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

Weakness type

CWE-362

CVE-2021-47577 is a Race Condition vulnerability

What is Race Condition?

The product contains a code sequence that can run concurrently with other code, creating unexpected states. Learn more on MITRE CWE

Affected versions

Linux kernel versions 5.13 and later are affected. Fixed in 5.15.11, 5.16 and their respective stable series.

Affected from

≥ 5.13

Fixed in

✓ 5.15.11 5.15.x ✓ 5.16

References

2 total

Kernel Git
https://git.kernel.org/stable/c/4b4e5bbf9386d4ec21d91c0cb0fd60b9bba778ec

Patch
Kernel Git
https://git.kernel.org/stable/c/71a85387546e50b1a37b0fa45dadcae3bfb35cf6

Patch

Details

CVE ID CVE-2021-47577

Severity Medium

CVSS score 4.7 / 10

CVSS version 3.1

Published 2024-06-19

Modified 2025-09-29

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-47577?

CVE-2021-47577 is a Medium severity Linux kernel vulnerability with a CVSS score of 4.7 out of 10 , classified as a Race Condition flaw (CWE-362) . It affects Linux kernel versions from 5.13 onward and has been patched in 5.15.11 and 5.16. CVE-2021-47577 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47577?

CVE-2021-47577 has a CVSS score of 4.7 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2021-47577?

Yes. CVE-2021-47577 has been patched. Fixed versions include 5.15.11 and 5.16. If you are running Linux kernel 5.13 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-47577 actively exploited?

No. CVE-2021-47577 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.