CVE-2019-20794Public exploit

Local denial of service via uninterruptible FUSE requests

Published May 9, 2020 · Updated Aug 5, 2024

Resource exhaustion in Linux kernel 4.18 through 5.6.11 allows local users to hang FUSE tasks until system reboot. The FUSE request_wait_answer path leaves an in-flight request in uninterruptible sleep after PID 1 of the request's PID namespace terminates, so the FUSE connection and its namespaces never tear down. Exploitation requires unprivileged user namespaces, a user-mounted FUSE filesystem, and local low-privileged access; repeated triggers permanently lock resources until reboot.

CVSS severity4.7
Medium
EPSS probability0.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in Linux kernel 4.18 through 5.6.11 allows local users to hang FUSE tasks until system reboot. The FUSE request_wait_answer path leaves an in-flight request in uninterruptible sleep after PID 1 of the request's PID namespace terminates, so the FUSE connection and its namespaces never tear down. Exploitation requires unprivileged user namespaces, a user-mounted FUSE filesystem, and local low-privileged access; repeated triggers permanently lock resources until reboot.

The record

CVE
CVE-2019-20794
Published
May 9, 2020
Updated
Aug 5, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-772, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 9, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.7NIST NVDAV:L/AC:M/Au:N/C:N/I:N/A:C
4.7NIST NVDCVSS:3.1/AV:L/AC:H/PR:L/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-772Missing Release of Resource after Effective Lifetime
T1499.004Application or System Exploitation

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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