CVE-2020-25639Public exploit

System crash via failed Nouveau channel initialization

Published Mar 4, 2021 · Updated Aug 4, 2024

NULL pointer dereference in the Nouveau driver in Linux Kernel before 5.12-rc1 allows local users to crash the system via a channel-allocation ioctl. When nouveau_channel_new encounters a channel-initialization error, it deletes the channel but continues into nouveau_svmm_join and dereferences the cleared channel pointer. An authorized local user in the render group can trigger the faulty DRM_IOCTL_NOUVEAU_CHANNEL_ALLOC path, causing a kernel oops and system crash.

CVSS severity4.4
Medium
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in the Nouveau driver in Linux Kernel before 5.12-rc1 allows local users to crash the system via a channel-allocation ioctl. When nouveau_channel_new encounters a channel-initialization error, it deletes the channel but continues into nouveau_svmm_join and dereferences the cleared channel pointer. An authorized local user in the render group can trigger the faulty DRM_IOCTL_NOUVEAU_CHANNEL_ALLOC path, causing a kernel oops and system crash.

The record

CVE
CVE-2020-25639
Published
Mar 4, 2021
Updated
Aug 4, 2024
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-476, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 4, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Linux kernel versions prior to 5.12-rc1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=Linux kernel versions prior to 5.12-rc1

Published CVSS scores

4.4Ubuntu Security TeamCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
4.9NIST NVDAV:L/AC:L/Au:N/C:N/I:N/A:C
4.4NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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