CVE-2019-20044: In Zsh before 5.8, attackers able to execute commands can regain privileges dropped by the --no-PRIVILEGED opt

Q: How do I fix CVE-2019-20044?

zsh: upgrade to 5.8; fedora: mitigate or apply the listed mitigation; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2019-20044 being exploited?

CVE-2019-20044 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-2019-20044 affect?

CVE-2019-20044 affects zsh, fedora, debian linux. Severity is high (CVSS 7.8). In Zsh before 5.8, attackers able to execute commands can regain privileges dropped by the --no-PRIVILEGED option. Zsh fails to overwrite the saved uid, so the original privileges can be restored by executing MODULE_PATH=/dir/with/module zm

Q: How urgent is CVE-2019-20044?

Priority 43/100. High severity; On your watchlist

This month

HIGH 7.8WATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2019-20044 is a high-severity flaw (CVSS 7.8) affecting zsh, fedora, debian linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In Zsh before 5.8, attackers able to execute commands can regain privileges dropped by the --no-PRIVILEGED option. Zsh fails to overwrite the saved uid, so the original privileges can be restored by executing MODULE_PATH=/dir/with/module zmodload with a module that calls setuid().

Why this priority

High severity
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.5% (top 58%)
CISA exploited list	No
Weakness	CWE-273
Published	2020-02-24
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: apple · debian · fedoraproject · zsh

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

Am I affected?

Timeline

2020-02-24 14:15 UTCPublished CVE record published
2026-06-17 02:29 UTCUpdated Record last modified

zsh zsh UPGRADE

Affected: < 5.8

Fixed in: 5.8

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 5.8 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade zsh

Note

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

fedoraproject fedora MITIGATE

Affected: 30 · 31

Fixed in: no fixed release known

Safe to downgrade to: a release before 30

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.

debian debian linux MITIGATE

Affected: 8.0 · 9.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.0

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.

apple ipados UPGRADE

Affected: < 13.5

Fixed in: 13.5

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.

apple iphone os UPGRADE

Affected: < 13.5

Fixed in: 13.5

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.

apple mac os x UPGRADE

Affected: < 10.15.5 · >= 10.13.0 and < 10.13.6 · >= 10.14.0 and < 10.14.6 · >= 10.15 and < 10.15.5 · 10.13.6 · 10.13.6 security_update_2018-002 · 10.13.6 security_update_2018-003 · 10.13.6 security_update_2019-001

Fixed in: 10.13.6, 10.14.6, 10.15.5

Safe to downgrade to: a release before 10.13.0

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-2019-20044?

zsh: upgrade to 5.8; fedora: mitigate or apply the listed mitigation; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2019-20044 being exploited?

CVE-2019-20044 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-2019-20044 affect?

CVE-2019-20044 affects zsh, fedora, debian linux. Severity is high (CVSS 7.8). In Zsh before 5.8, attackers able to execute commands can regain privileges dropped by the --no-PRIVILEGED option. Zsh fails to overwrite the saved uid, so the original privileges can be restored by executing MODULE_PATH=/dir/with/module zm

How urgent is CVE-2019-20044?

Priority 43/100. High severity; On your watchlist

Software pages

Debian vulnerabilities · iPadOS vulnerabilities

Related CVEs

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References

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