CVE-2020-5239: In Mailu before version 1.7, an authenticated user can exploit a vulnerability in Mailu fetchmail script and g

Q: How do I fix CVE-2020-5239?

mailu: upgrade to 1.7. Exact commands for each OS are on this page.

Q: Is CVE-2020-5239 being exploited?

CVE-2020-5239 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-2020-5239 affect?

CVE-2020-5239 affects mailu. Severity is high (CVSS 8.7). In Mailu before version 1.7, an authenticated user can exploit a vulnerability in Mailu fetchmail script and gain full access to a Mailu instance. Mailu servers that have open registration or untrusted users are most impacted. The master an

This month

HIGH 8.7UPGRADE

CVE-2020-5239 is a high-severity flaw (CVSS 8.7) affecting mailu. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In Mailu before version 1.7, an authenticated user can exploit a vulnerability in Mailu fetchmail script and gain full access to a Mailu instance. Mailu servers that have open registration or untrusted users are most impacted. The master and 1.7 branches are patched on our git repository. All Docker images published on docker.io/mailu for tags 1.5, 1.6, 1.7 and master are patched. For detailed instructions about patching and securing the server a

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.7 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.9% (top 41%)
CISA exploited list	No
Weakness	CWE-863
Published	2020-02-13
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: mailu

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

Am I affected?

Timeline

2020-02-13 01:15 UTCPublished CVE record published
2026-06-17 03:21 UTCUpdated Record last modified

mailu mailu UPGRADE

Affected: < 1.7

Fixed in: 1.7

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 1.7 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mailu

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-2020-5239?

mailu: upgrade to 1.7. Exact commands for each OS are on this page.

Is CVE-2020-5239 being exploited?

CVE-2020-5239 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-2020-5239 affect?

CVE-2020-5239 affects mailu. Severity is high (CVSS 8.7). In Mailu before version 1.7, an authenticated user can exploit a vulnerability in Mailu fetchmail script and gain full access to a Mailu instance. Mailu servers that have open registration or untrusted users are most impacted. The master an

How urgent is CVE-2020-5239?

Priority 45/100. High severity

Software pages

Docker vulnerabilities · Git vulnerabilities

References

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