CVE-2020-3979: InstallBuilder for Qt Windows (versions prior to 20.7.0) installers look for plugins at a predictable location

Q: How do I fix CVE-2020-3979?

installbuilder: upgrade to 20.7.0. Exact commands for each OS are on this page.

Q: Is CVE-2020-3979 being exploited?

CVE-2020-3979 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-2020-3979 affect?

CVE-2020-3979 affects installbuilder. Severity is high (CVSS 7.8). InstallBuilder for Qt Windows (versions prior to 20.7.0) installers look for plugins at a predictable location at initialization time, writable by non-admin users. While those plugins are not required, they are loaded if present, which coul

Routine

HIGH 7.8UPGRADE

CVE-2020-3979 is a high-severity flaw (CVSS 7.8) affecting installbuilder. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

InstallBuilder for Qt Windows (versions prior to 20.7.0) installers look for plugins at a predictable location at initialization time, writable by non-admin users. While those plugins are not required, they are loaded if present, which could allow an attacker to plant a malicious library which could result in code execution with the security scope of the installer.

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.4% (top 68%)
CISA exploited list	No
Weakness	CWE-427
Published	2020-09-18
Last modified	2026-06-17

Publisher (CNA): VMware · Vendor: installbuilder

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

Am I affected?

Timeline

2020-09-18 18:15 UTCPublished CVE record published
2026-06-17 03:19 UTCUpdated Record last modified

installbuilder installbuilder UPGRADE

Affected: < 20.7.0

Fixed in: 20.7.0

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 20.7.0 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade installbuilder

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-2020-3979?

installbuilder: upgrade to 20.7.0. Exact commands for each OS are on this page.

Is CVE-2020-3979 being exploited?

CVE-2020-3979 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-2020-3979 affect?

CVE-2020-3979 affects installbuilder. Severity is high (CVSS 7.8). InstallBuilder for Qt Windows (versions prior to 20.7.0) installers look for plugins at a predictable location at initialization time, writable by non-admin users. While those plugins are not required, they are loaded if present, which coul

How urgent is CVE-2020-3979?

Priority 35/100. High severity

Software pages

Windows vulnerabilities

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References

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