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Vulnerability record · CVE-2021-20239 · published 28 May 2021

CVE-2021-20239: Linux kernel memory buffer overflow vulnerability

Linux · Linux Kernel

A flaw was found in the Linux kernel in versions before 5.4.92 in the BPF protocol. This flaw allows an attacker with a local account to leak information about kernel internal addresses. The highest threat from this vulnerability is to confidentiality.

3.3 CVSS 3.1 Low EPSS 0.26% · top 84.6% CWE-822 · CWE-822CWE-119 · Memory buffer overflow
3.3CVSS 3.1 base score, v2 2.1
0.26%EPSS exploitation probability, 30 days
NoNot in CISA KEV
3Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

Description

A flaw was found in the Linux kernel in versions before 5.4.92 in the BPF protocol. This flaw allows an attacker with a local account to leak information about kernel internal addresses. The highest threat from this vulnerability is to confidentiality.

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

Affected products

3 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://bugzilla.redhat.com/show_bug.cgi?id=1923636 Issue TrackingThird Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1923636 Issue TrackingThird Party Advisory

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Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2021-20239), CISA KEV, FIRST EPSS (scores of 2026-09-29). This page is refreshed as NVD updates the record.