CVE-2021-3934: ohmyzsh is vulnerable to Improper Neutralization of Special Elements used in an OS Command

Q: How do I fix CVE-2021-3934?

oh my zsh: upgrade to 2021-11-11. Exact commands for each OS are on this page.

Q: Is CVE-2021-3934 being exploited?

CVE-2021-3934 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-2021-3934 affect?

CVE-2021-3934 affects oh my zsh. Severity is high (CVSS 7.5). ohmyzsh is vulnerable to Improper Neutralization of Special Elements used in an OS Command

Routine

HIGH 7.5UPGRADE

CVE-2021-3934 is a high-severity flaw (CVSS 7.5) affecting oh my zsh. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

ohmyzsh is vulnerable to Improper Neutralization of Special Elements used in an OS Command

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.6% (top 50%)
CISA exploited list	No
Weakness	CWE-78
Published	2021-11-12
Last modified	2026-06-17

Publisher (CNA): huntr.dev · Vendor: planetargon

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

Am I affected?

Timeline

2021-11-12 12:15 UTCPublished CVE record published
2026-06-17 04:06 UTCUpdated Record last modified

planetargon oh my zsh UPGRADE

Affected: < 2021-11-11

Fixed in: 2021-11-11

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 2021-11-11 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade oh-my-zsh

Note

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

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-2021-3934?

oh my zsh: upgrade to 2021-11-11. Exact commands for each OS are on this page.

Is CVE-2021-3934 being exploited?

CVE-2021-3934 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-2021-3934 affect?

CVE-2021-3934 affects oh my zsh. Severity is high (CVSS 7.5). ohmyzsh is vulnerable to Improper Neutralization of Special Elements used in an OS Command

How urgent is CVE-2021-3934?

Priority 39/100. High severity

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References

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