CVE-2016-7543: Bash before 4.4 allows local users to execute arbitrary commands with root privileges via crafted SHELLOPTS an

Q: How do I fix CVE-2016-7543?

bash: upgrade to newer than 4.3; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2016-7543 being exploited?

CVE-2016-7543 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-2016-7543 affect?

CVE-2016-7543 affects bash, fedora. Severity is high (CVSS 8.4). Bash before 4.4 allows local users to execute arbitrary commands with root privileges via crafted SHELLOPTS and PS4 environment variables.

This month

HIGH 8.4UPGRADEMITIGATE

CVE-2016-7543 is a high-severity flaw (CVSS 8.4) affecting bash, fedora. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Bash before 4.4 allows local users to execute arbitrary commands with root privileges via crafted SHELLOPTS and PS4 environment variables.

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.4 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 52%)
CISA exploited list	No
Weakness	CWE-20
Published	2017-01-19
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: fedoraproject · gnu

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

Am I affected?

Timeline

2017-01-19 20:59 UTCPublished CVE record published
2026-06-17 00:53 UTCUpdated Record last modified

gnu bash UPGRADE

Affected: <= 4.3

Fixed in: newer than 4.3

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 4.3 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade bash

Note

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

fedoraproject fedora MITIGATE

Affected: 23 · 24 · 25

Fixed in: no fixed release known

Safe to downgrade to: a release before 23

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-2016-7543?

bash: upgrade to newer than 4.3; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2016-7543 being exploited?

CVE-2016-7543 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-2016-7543 affect?

CVE-2016-7543 affects bash, fedora. Severity is high (CVSS 8.4). Bash before 4.4 allows local users to execute arbitrary commands with root privileges via crafted SHELLOPTS and PS4 environment variables.

How urgent is CVE-2016-7543?

Priority 41/100. High severity

Related CVEs

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CVE-2019-18276 HIGH 7.8 UPGRADE MITIGATE An issue was discovered in disable_priv_mode in shell.c in GNU Bash through 5.0 patch 11
CVE-2019-9924 HIGH 7.8 UPGRADE MITIGATE rbash in Bash before 4.4-beta2 did not prevent the shell user from modifying BASH_CMDS, thus allowing the user
CVE-2017-5932 HIGH 7.8 MITIGATE The path autocompletion feature in Bash 4.4 allows local users to gain privileges via a crafted filename start
CVE-2016-9401 MEDIUM 5.5 UPGRADE MITIGATE popd in bash might allow local users to bypass the restricted shell and cause a use-after-free via a crafted a

References

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