SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-20239

This flaw allows an attacker with a local account to leak information about kernel internal addresses.

LOW 3.3EPSS 0.26%

Does this matter?

Lower severity and a low EPSS score (0.26%). Track it; it rarely justifies an emergency change on its own.

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
3.3 LOWCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
EPSS
0.26% probability · 17th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-822, CWE-119
Affected
linux/linux kernel · redhat/enterprise linux · fedoraproject/fedora
Source
secalert@redhat.com
EPSS trend
0%3%5%26 October 2026: 0.26%26 October 202626 October 2026

EPSS 0.3% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.