How severe is CVE-2021-47386?

CVE-2021-47386 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-47386 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-47386?

CVE-2021-47386 primarily affects Linux Linux Kernel. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-47386?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2021-47386 have an EU (EUVD) identifier?

Yes. CVE-2021-47386 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34391.

When was CVE-2021-47386 published?

CVE-2021-47386 was published on 2024-05-21 and last updated on 2026-06-17.

CVE-2021-47386

CVE-2021-47386 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.

Key facts

Severity: High (CVSS 3.x base score 7.8)
EPSS exploit prediction: 0% (17th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2021-34391
Weakness: CWE-476
Affected product: Linux Linux Kernel
Published: 2024-05-21
Last modified: 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: hwmon: (w83791d) Fix NULL pointer dereference by removing unnecessary structure field If driver read val value sufficient for (val & 0x08) && (!(val & 0x80)) && ((val & 0x7) == ((val >> 4) & 0x7)) from device then Null pointer dereference occurs. (It is possible if tmp = 0b0xyz1xyz, where same literals mean same numbers) Also lm75[] does not serve a purpose anymore after switching to devm_i2c_new_dummy_device() in w83791d_detect_subclients(). The patch fixes possible NULL pointer dereference by removing lm75[]. Found by Linux Driver Verification project (linuxtesting.org). [groeck: Dropped unnecessary continuation lines, fixed multi-line alignment]

Frequently asked questions

What is CVE-2021-47386?: In the Linux kernel, the following vulnerability has been resolved: hwmon: (w83791d) Fix NULL pointer dereference by removing unnecessary structure field If driver read val value sufficient for (val & 0x08) && (!(val & 0x80)) && ((val & 0x7) == ((val >> 4) & 0x7)) from device then Null pointer dereference occurs. (It is possible if tmp = 0b0xyz1xyz, where same literals mean same numbers) Also lm75[] does not serve a purpose anymore after switching to devm_i2c_new_dummy_device() in w83791d_detect_subclients(). The patch fixes possible NULL pointer dereference by removing lm75[]. Found by Linux Driver Verification project (linuxtesting.org). [groeck: Dropped unnecessary continuation lines, fixed multi-line alignment]
How severe is CVE-2021-47386?: CVE-2021-47386 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-47386 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-47386?: CVE-2021-47386 primarily affects Linux Linux Kernel. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-47386?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2021-47386 have an EU (EUVD) identifier?: Yes. CVE-2021-47386 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34391.
When was CVE-2021-47386 published?: CVE-2021-47386 was published on 2024-05-21 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:*

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