CVE-2020-5291: Bubblewrap (bwrap) before version 0.4.1, if installed in setuid mode and the kernel supports unprivileged user

Q: How do I fix CVE-2020-5291?

bubblewrap: upgrade to 0.4.1; debian linux: mitigate or apply the listed mitigation; arch linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2020-5291 being exploited?

CVE-2020-5291 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2020-5291 affect?

CVE-2020-5291 affects bubblewrap, debian linux, arch linux. Severity is high (CVSS 7.2). Bubblewrap (bwrap) before version 0.4.1, if installed in setuid mode and the kernel supports unprivileged user namespaces, then the `bwrap --userns2` option can be used to make the setuid process keep running as root while being traceable.

Q: How urgent is CVE-2020-5291?

Priority 45/100. High severity; On your watchlist

This month

HIGH 7.2WATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2020-5291 is a high-severity flaw (CVSS 7.2) affecting bubblewrap, debian linux, arch linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Bubblewrap (bwrap) before version 0.4.1, if installed in setuid mode and the kernel supports unprivileged user namespaces, then the `bwrap --userns2` option can be used to make the setuid process keep running as root while being traceable. This can in turn be used to gain root permissions. Note that this only affects the combination of bubblewrap in setuid mode (which is typically used when unprivileged user namespaces are not supported) and the

Why this priority

High severity
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.2 (High)
Attack vector	Local
Attack complexity	High
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.9% (top 40%)
CISA exploited list	No
Weakness	CWE-648, CWE-269
Published	2020-03-31
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: archlinux · centos · debian · projectatomic

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2020-03-31 18:15 UTCPublished CVE record published
2026-06-17 03:21 UTCUpdated Record last modified

projectatomic bubblewrap UPGRADE

Affected: < 0.4.1

Fixed in: 0.4.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy bubblewrap || rpm -q bubblewrap || bubblewrap --version

2. UPGRADE to 0.4.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade bubblewrap

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade bubblewrap

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

debian debian linux MITIGATE

Affected: 10.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 10.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

archlinux arch linux MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

centos centos MITIGATE

Affected: 7.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 7.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2020-5291?

bubblewrap: upgrade to 0.4.1; debian linux: mitigate or apply the listed mitigation; arch linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-5291 being exploited?

CVE-2020-5291 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2020-5291 affect?

CVE-2020-5291 affects bubblewrap, debian linux, arch linux. Severity is high (CVSS 7.2). Bubblewrap (bwrap) before version 0.4.1, if installed in setuid mode and the kernel supports unprivileged user namespaces, then the `bwrap --userns2` option can be used to make the setuid process keep running as root while being traceable.

How urgent is CVE-2020-5291?

Priority 45/100. High severity; On your watchlist

Software pages

Debian vulnerabilities

Related CVEs

CVE-2019-12439 HIGH 7.4 UPGRADE bubblewrap.c in Bubblewrap before 0.3.3 misuses temporary directories in /tmp as a mount point
CVE-2017-5226 CRITICAL 10.0 UPGRADE When executing a program via the bubblewrap sandbox, the nonpriv session can escape to the parent session by u
CVE-2016-8659 HIGH 7.0 UPGRADE Bubblewrap before 0.1.3 sets the PR_SET_DUMPABLE flag, which might allow local users to gain privileges by att

References

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