CVE-2019-6440: Zemana AntiMalware before 3.0.658 Beta mishandles update logic.

This week

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2019-6440 is a critical-severity flaw (CVSS 9.8) affecting antimalware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Zemana AntiMalware before 3.0.658 Beta mishandles update logic.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	3.0% (top 13%)
CISA exploited list	No
Weakness	CWE-19
Published	2019-01-16
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: zemana

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

Am I affected?

Timeline

2019-01-16 04:29 UTCPublished CVE record published
2026-06-17 02:39 UTCUpdated Record last modified

zemana antimalware DOWNGRADE

Affected: 2.1.1.353 beta · 2.1.1.543 beta · 2.1.1.621 beta · 2.1.1.929 beta · 2.2.1.105 beta · 2.2.1.234 beta · 2.2.1.460 beta · 2.4.1.100 beta

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.1.1.353

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 2.1.1.353 (Debian / Ubuntu)

apt-cache madison antimalware sudo apt install antimalware=<VERSION_BEFORE_2.1.1.353> sudo apt-mark hold antimalware

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list antimalware sudo dnf downgrade antimalware-<VERSION_BEFORE_2.1.1.353> sudo dnf versionlock add antimalware

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

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-2019-6440?

antimalware: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2019-6440 being exploited?

CVE-2019-6440 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-2019-6440 affect?

CVE-2019-6440 affects antimalware. Severity is critical (CVSS 9.8). Zemana AntiMalware before 3.0.658 Beta mishandles update logic.

How urgent is CVE-2019-6440?

Priority 61/100. Critical severity; Remotely exploitable, no login, no user action

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References

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