CVE-2000-0198: Buffer overflow in POP3 and IMAP servers in the MERCUR mail server suite allows remote attackers to cause a de

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MEDIUM 5.0DOWNGRADEDOWNGRADEDOWNGRADE

CVE-2000-0198 is a medium-severity flaw (CVSS 5.0) affecting mercur imap4 server, mercur mailserver, mercur pop3 server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Buffer overflow in POP3 and IMAP servers in the MERCUR mail server suite allows remote attackers to cause a denial of service.

Why this priority

EPSS top 5%: very likely to be exploited
Public exploit reference

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

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	8.4% (top 5%)
CISA exploited list	No
Published	2000-03-15
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: atrium software

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2000-03-15 05:00 UTCPublished CVE record published
2026-06-16 21:51 UTCUpdated Record last modified

atrium software mercur imap4 server DOWNGRADE

Affected: 3.20.01

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.20.01

1. Check installed version

apt-cache policy mercur-imap4-server || rpm -q mercur-imap4-server || mercur-imap4-server --version

2. No fixed release: DOWNGRADE to a release before 3.20.01 (Debian / Ubuntu)

apt-cache madison mercur-imap4-server sudo apt install mercur-imap4-server=<VERSION_BEFORE_3.20.01> sudo apt-mark hold mercur-imap4-server

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

dnf --showduplicates list mercur-imap4-server sudo dnf downgrade mercur-imap4-server-<VERSION_BEFORE_3.20.01> sudo dnf versionlock add mercur-imap4-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.

atrium software mercur mailserver DOWNGRADE

Affected: 3.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.2

1. Check installed version

apt-cache policy mercur-mailserver || rpm -q mercur-mailserver || mercur-mailserver --version

2. No fixed release: DOWNGRADE to a release before 3.2 (Debian / Ubuntu)

apt-cache madison mercur-mailserver sudo apt install mercur-mailserver=<VERSION_BEFORE_3.2> sudo apt-mark hold mercur-mailserver

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

dnf --showduplicates list mercur-mailserver sudo dnf downgrade mercur-mailserver-<VERSION_BEFORE_3.2> sudo dnf versionlock add mercur-mailserver

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.

atrium software mercur pop3 server DOWNGRADE

Affected: 3.20.01

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.20.01

1. Check installed version

apt-cache policy mercur-pop3-server || rpm -q mercur-pop3-server || mercur-pop3-server --version

2. No fixed release: DOWNGRADE to a release before 3.20.01 (Debian / Ubuntu)

apt-cache madison mercur-pop3-server sudo apt install mercur-pop3-server=<VERSION_BEFORE_3.20.01> sudo apt-mark hold mercur-pop3-server

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

dnf --showduplicates list mercur-pop3-server sudo dnf downgrade mercur-pop3-server-<VERSION_BEFORE_3.20.01> sudo dnf versionlock add mercur-pop3-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.

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Exploit-DB: Atrium Software Mercur Mail Server 3.2 - Multiple Buffer Overflows (1)
Exploit-DB: Atrium Software Mercur Mail Server 3.2 - Multiple Buffer Overflows (2)

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-2000-0198?

mercur imap4 server: downgrade or apply the listed mitigation; mercur mailserver: downgrade or apply the listed mitigation; mercur pop3 server: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2000-0198 being exploited?

CVE-2000-0198 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-2000-0198 affect?

CVE-2000-0198 affects mercur imap4 server, mercur mailserver, mercur pop3 server. Severity is medium (CVSS 5.0). Buffer overflow in POP3 and IMAP servers in the MERCUR mail server suite allows remote attackers to cause a denial of service.

How urgent is CVE-2000-0198?

Priority 46/100. EPSS top 5%: very likely to be exploited; Public exploit reference

Related CVEs

CVE-2000-0239 MEDIUM 5.0 DOWNGRADE DOWNGRADE Buffer overflow in the MERCUR WebView WebMail server allows remote attackers to cause a denial of service via

References

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