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MEDIUM

CVE-2020-25656

CVSS v3

4.1

MEDIUM

EPSS Score

0.4 %

exploit probability, as of 2026-10-19

CISA KEV

No

known exploited

Exploitation

—

SSVC status

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Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

  • CVE-2020-25656 Red Hat Product Security335 products fixed · 17 known affected

    kernel: use-after-free in read in vt_do_kdgkb_ioctl

    kernel as a component of Red Hat Enterprise Linux 7 · kernel-abi-whitelists as a component of Red Hat Enterprise Linux 7 · kernel-alt.src as a component of Red Hat Enterprise Linux 7

  • RHSA-2024:2950 Red Hat Product Security30 products fixed

    Red Hat Security Advisory: kernel-rt security and bug fix update

  • RHSA-2024:3138 Red Hat Product Security120 products fixed

    Red Hat Security Advisory: kernel security, bug fix, and enhancement update

  • RHSA-2021:0856 Red Hat Product Security155 products fixed

    Red Hat Security Advisory: kernel security and bug fix update

  • RHSA-2021:0857 Red Hat Product Security30 products fixed

    Red Hat Security Advisory: kernel-rt security and bug fix update

Full record on NVD

Description

A flaw was found in the Linux kernel. A use-after-free was found in the way the console subsystem was using ioctls KDGKBSENT and KDSKBSENT. A local user could use this flaw to get read memory access out of bounds. The highest threat from this vulnerability is to data confidentiality.

Technical details

Published
2020-12-02

Frequently asked questions

What is CVE-2020-25656?

A flaw was found in the Linux kernel. A use-after-free was found in the way the console subsystem was using ioctls KDGKBSENT and KDSKBSENT. A local user could use this flaw to get read memory access out of bounds. The highest threat from this vulnerability is to data confidentiality.

Is CVE-2020-25656 actively exploited?

Active exploitation of CVE-2020-25656 has not been confirmed. Its EPSS score was 0.4% on 2026-10-19, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-25656?

CVE-2020-25656 has a CVSS v3 base score of 4.1 (MEDIUM severity).

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