CVE-2019-20794

An issue was discovered in the Linux kernel 4.18 through 5.6.11 when unprivileged user namespaces are allowed. A user can create their own PID namespace, and mount a FUSE filesystem. Upon interaction with this FUSE filesystem, if the userspace component is terminated via a kill of the PID namespace's pid 1, it will result in a hung task, and resources being permanently locked up until system reboot. This can result in resource exhaustion.

CVSS 3.1

4.7CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS

0.5% chance of exploitation in the next 30 days; higher than 43% of CVEs (scores of 2026-10-25)

CWE

CWE-772

Published

2020-05-09

Modified

2026-10-08

Record from

the NVD, synced 2026-10-19

Affected

• linux:linux_kernel

References

• http://www.openwall.com/lists/oss-security/2020/08/24/1
• https://github.com/sargun/fuse-example
• https://security.netapp.com/advisory/ntap-20200608-0001/
• https://sourceforge.net/p/fuse/mailman/message/36598753/
• http://www.openwall.com/lists/oss-security/2020/08/24/1

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