CVE-2020-14066: IceWarp Email Server 12.3.0.1 allows remote attackers to upload JavaScript files that are dangerous for client

This month

HIGH 8.8DOWNGRADE

CVE-2020-14066 is a high-severity flaw (CVSS 8.8) affecting mail server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

IceWarp Email Server 12.3.0.1 allows remote attackers to upload JavaScript files that are dangerous for clients to access.

Why this priority

High severity

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

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	1.8% (top 22%)
CISA exploited list	No
Weakness	CWE-434
Published	2020-07-15
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: icewarp

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

Am I affected?

Timeline

2020-07-15 20:15 UTCPublished CVE record published
2026-06-17 02:54 UTCUpdated Record last modified

icewarp mail server DOWNGRADE

Affected: 12.3.0.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 12.3.0.1

1. Check installed version

apt-cache policy mail-server || rpm -q mail-server || mail-server --version

2. No fixed release: DOWNGRADE to a release before 12.3.0.1 (Debian / Ubuntu)

apt-cache madison mail-server sudo apt install mail-server=<VERSION_BEFORE_12.3.0.1> sudo apt-mark hold mail-server

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

dnf --showduplicates list mail-server sudo dnf downgrade mail-server-<VERSION_BEFORE_12.3.0.1> sudo dnf versionlock add mail-server

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-2020-14066?

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

Is CVE-2020-14066 being exploited?

CVE-2020-14066 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-2020-14066 affect?

CVE-2020-14066 affects mail server. Severity is high (CVSS 8.8). IceWarp Email Server 12.3.0.1 allows remote attackers to upload JavaScript files that are dangerous for clients to access.

How urgent is CVE-2020-14066?

Priority 50/100. High severity

Related CVEs

CVE-2025-2848 MEDIUM 6.3 UPGRADE A vulnerability in Synology Mail Server allows remote authenticated attackers to read and write non-sensitive
CVE-2021-36580 MEDIUM 6.1 UPGRADE UPGRADE Open Redirect vulnerability exists in IceWarp MailServer IceWarp Server Deep Castle 2 Update 1 (13.0.1.2) via
CVE-2025-40632 MEDIUM 6.1 DOWNGRADE Cross-site scripting (XSS) in Icewarp Mail Server affecting version 11.4.0
CVE-2025-40631 MEDIUM 6.1 DOWNGRADE HTTP host header injection vulnerability in Icewarp Mail Server affecting version 11.4.0
CVE-2025-40630 MEDIUM 6.1 DOWNGRADE Open redirection vulnerability in IceWarp Mail Server affecting version 11.4.0

References

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