CVE-2019-15791

mediumpriority · track · 41EPSS 0.013 · 71 %ileexploit · functionalEURUUS

grimoire priorityP1 · Urgent

Exploitable?

Public exploit

1 exploit · functional

Likely / severe?

1.32% (71st) EPSS

CVSS 4.6 · medium

Is it mine?

15 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · fstec_bdu · nvd

EPSS · scored 2026-10-26

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.

cvss

Technical severity, 0–10. One row per scoring source.

7.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4.6–7.8

v2.04.6mediumAV:L/AC:L/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 3.9 · impact 6.4

v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 1.8 · impact 5.9

v3.16.2mediumAV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU

v3.17.1highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:Hsecondary · ENISA EU

v3.17.1highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:Hsecondary · security@ubuntu.comexploitability 1.8 · impact 5.2

v3.17.1highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-191USprimaryCWE-400USCWE-672US

exploits (1)

Public proof-of-concept and weaponised exploit code.

EDB-47693Ubuntu 19.10 - Refcount Underflow and Type Confusion in shiftfsfunctional · exploit_db

affected products (15)

Products and version ranges known to be affected.

Ubuntu Shiftfs in the Linux kernel5.0 kernel → 5.0.0-35.38enisa_euvdEU
Ubuntu Shiftfs in the Linux kernel5.3.0-11.12 → 5.3 kernel*enisa_euvdEU
Canonical Ltd. Ubuntu≤ 19.04fstec_bduRU
Canonical Ltd. Ubuntu≤ 19.10fstec_bduRU
Canonical Ltd. Ubuntu≤ 18.04 LTSfstec_bduRU
ООО «РусБИТех-Астра» Astra Linux Common Edition≤ 2.12 «Орёл»fstec_bduRU
ООО «РусБИТех-Астра» Astra Linux Special Edition для «Эльбрус»≤ 8.1 «Ленинград»fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 9fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 10fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 8fstec_bduRU
Сообщество свободного программного обеспечения Linux≤ 4.9.228fstec_bduRU
canonical ubuntu linux= 18.04nvdUScpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:*:*:*:*
canonical ubuntu linux= 19.04nvdUScpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:*:*:*:*
linux linux kernel= 5.0nvdUScpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux kernel= 5.3nvdUScpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu nvd NVD CVE.org MITRE

published 2020-04-24modified 2026-06-17

related (720)

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+715 more

references (19)

External citations — patches, advisories, analysis.

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