CVE-2019-15791

Name: CVE-2019-15791
Creator: NVD / NIST
Published: 2020-04-24T00:15:11.697+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 1.32%

Last modified Jun 17, 2026

CVE-2019-15791 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, shiftfs_btrfs_ioctl_fd_replace() installs an fd referencing a file from the lower filesystem without taking an additional reference to that file. After the btrfs ioctl completes this fd is closed, which then puts a reference to that file, leading to a refcount underflow.. EPSS estimates a 1.32% chance of exploitation in the next 30 days.

Description

In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, shiftfs_btrfs_ioctl_fd_replace() installs an fd referencing a file from the lower filesystem without taking an additional reference to that file. After the btrfs ioctl completes this fd is closed, which then puts a reference to that file, leading to a refcount underflow.

Metrics

CVSS 3.1

7.8/10

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

EPSS Probability

1.32%

67.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	5.0
Linux	Linux Kernel	5.3
Canonical	Ubuntu Linux	18.04
Canonical	Ubuntu Linux	19.04

References

https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?id=601a64857b3d7040ca15c39c929e6b9db3373ec1Mailing List, Patch, Third Party Advisory
https://usn.ubuntu.com/usn/usn-4183-1Third Party Advisory
https://usn.ubuntu.com/usn/usn-4184-1Third Party Advisory
https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?id=601a64857b3d7040ca15c39c929e6b9db3373ec1Mailing List, Patch, Third Party Advisory
https://usn.ubuntu.com/usn/usn-4183-1Third Party Advisory
https://usn.ubuntu.com/usn/usn-4184-1Third Party Advisory

Timeline

Published: Apr 24, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-15791?

How severe is CVE-2019-15791?

CVE-2019-15791 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 1.32% probability of exploitation in the next 30 days.

How do I fix CVE-2019-15791?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2019-15791?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST