CVE-2000-0840: Buffer overflow in XMail POP3 server before version 0.59 allows remote attackers to execute arbitrary commands

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HIGH 10.0DOWNGRADE

CVE-2000-0840 is a high-severity flaw (CVSS 10.0) affecting xmail. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Buffer overflow in XMail POP3 server before version 0.59 allows remote attackers to execute arbitrary commands via a long USER command.

Why this priority

Critical severity
EPSS top 7%: very likely to be exploited

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

Risk facts

CVSS score	10.0 (High)
EPSS exploit chance	5.4% (top 7%)
CISA exploited list	No
Published	2000-11-14
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: davide libenzi

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

Am I affected?

Timeline

2000-11-14 05:00 UTCPublished CVE record published
2026-06-16 21:52 UTCUpdated Record last modified

davide libenzi xmail DOWNGRADE

Affected: 0.58

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.58

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 0.58 (Debian / Ubuntu)

apt-cache madison xmail sudo apt install xmail=<VERSION_BEFORE_0.58> sudo apt-mark hold xmail

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

dnf --showduplicates list xmail sudo dnf downgrade xmail-<VERSION_BEFORE_0.58> sudo dnf versionlock add xmail

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-2000-0840?

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

Is CVE-2000-0840 being exploited?

CVE-2000-0840 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-2000-0840 affect?

CVE-2000-0840 affects xmail. Severity is high (CVSS 10.0). Buffer overflow in XMail POP3 server before version 0.59 allows remote attackers to execute arbitrary commands via a long USER command.

How urgent is CVE-2000-0840?

Priority 58/100. Critical severity; EPSS top 7%: very likely to be exploited

Related CVEs

CVE-2005-2943 HIGH 7.5 DOWNGRADE Stack-based buffer overflow in sendmail in XMail before 1.22 allows remote attackers to execute arbitrary code
CVE-2001-0192 HIGH 10.0 UPGRADE Buffer overflows in CTRLServer in XMail allows attackers to execute arbitrary commands via the cfgfileget or d
CVE-2000-0841 HIGH 10.0 DOWNGRADE Buffer overflow in XMail POP3 server before version 0.59 allows remote attackers to execute arbitrary commands

References

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