CVE-2016-7543

CVE-2016-7543 is a high-severity vulnerability in Gnu Bash with a CVSS 3.x base score of 8.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

• Severity: High (CVSS 3.x base score 8.4)
• CVSS v2: 7.2
• EPSS exploit prediction: 1% (45th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-20
• Affected product: Gnu Bash
• Published: 2017-01-19
• Last modified: 2026-06-17

Description

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

Frequently asked questions

What is CVE-2016-7543?

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

How severe is CVE-2016-7543?

CVE-2016-7543 has a CVSS 3.x base score of 8.4, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2016-7543 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-7543?

CVE-2016-7543 primarily affects Gnu Bash. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-7543?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2016-7543 published?

CVE-2016-7543 was published on 2017-01-19 and last updated on 2026-06-17.

References

• http://rhn.redhat.com/errata/RHSA-2017-0725.html
• http://www.openwall.com/lists/oss-security/2016/09/26/9
• http://www.securityfocus.com/bid/93183
• http://www.securitytracker.com/id/1037812
• https://access.redhat.com/errata/RHSA-2017:1931
• https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05388115
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/F7XOQSHU63Y357NHU5FPTFBM6I3YOCQB/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OU3C756YPHDAAPFX76UGZBAQQQ5UMHS5/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Z2VRBSIPZDZ75ZQ2DLITHUIDW4W26KVR/
• https://lists.gnu.org/archive/html/bug-bash/2016-09/msg00018.html
• https://security.gentoo.org/glsa/201701-02

Affected products (4)

• cpe:2.3:a:gnu:bash:*:*:*:*:*:*:*:*
• cpe:2.3:o:fedoraproject:fedora:23:*:*:*:*:*:*:*
• cpe:2.3:o:fedoraproject:fedora:24:*:*:*:*:*:*:*
• cpe:2.3:o:fedoraproject:fedora:25:*:*:*:*:*:*:*

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