Is CVE-2021-47504 in the CISA KEV catalog?

No. CVE-2021-47504 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-47504?

CVE-2021-47504 has a CVSS v3 base score of 5.5 (MEDIUM).

What is the EPSS score for CVE-2021-47504?

CVE-2021-47504 has an EPSS score of 0.21% (11th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-47504?

Upgrade linux on debian 12 to 5.15.15-1 or later.

CVE & CISA-KEV Catalog

CVE-2021-47504

MEDIUM

5.5

CVSS v3

NVD

Description

In the Linux kernel, the following vulnerability has been resolved: io_uring: ensure task_work gets run as part of cancelations If we successfully cancel a work item but that work item needs to be processed through task_work, then we can be sleeping uninterruptibly in io_uring_cancel_generic() and never process it. Hence we don't make forward progress and we end up with an uninterruptible sleep warning. While in there, correct a comment that should be IFF, not IIF.

How to fix

Remediation Available

linuxDebian

Fixed in:5.15.15-1CVE-2021-47504

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorLocal

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

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

Exploit Intelligence

0.21%probability of exploitation in 30 days

11thpercentile

Low risk: more likely to be exploited than 11% of all known CVEs.

References

Patch2

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-09-29.