CVE-2006-5961: Buffer overflow in Mercury Mail Transport System 4.01b for Windows has unknown impact and attack vectors, as o

This month

HIGH 7.5DOWNGRADE

CVE-2006-5961 is a high-severity flaw (CVSS 7.5) affecting mercury mail transport system. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Buffer overflow in Mercury Mail Transport System 4.01b for Windows has unknown impact and attack vectors, as originally reported in a GLEG VulnDisco pack. NOTE: the provenance of this information is unknown; the details are obtained from third party information. The original researcher is reliable.

Why this priority

High severity
Public exploit reference

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

Risk facts

CVSS score	7.5 (High)
EPSS exploit chance	2.2% (top 18%)
CISA exploited list	No
Published	2006-11-17
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: pegasus

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

Am I affected?

Timeline

2006-11-17 01:07 UTCPublished CVE record published
2026-06-16 22:32 UTCUpdated Record last modified

pegasus mercury mail transport system DOWNGRADE

Affected: 4.0.1b

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.0.1b

1. Check installed version

apt-cache policy mercury-mail-transport-system || rpm -q mercury-mail-transport-system || mercury-mail-transport-system --version

2. No fixed release: DOWNGRADE to a release before 4.0.1b (Debian / Ubuntu)

apt-cache madison mercury-mail-transport-system sudo apt install mercury-mail-transport-system=<VERSION_BEFORE_4.0.1b> sudo apt-mark hold mercury-mail-transport-system

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

dnf --showduplicates list mercury-mail-transport-system sudo dnf downgrade mercury-mail-transport-system-<VERSION_BEFORE_4.0.1b> sudo dnf versionlock add mercury-mail-transport-system

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: Mercury/32 Mail Server 4.01a (Pegasus) - IMAP Buffer Overflow

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-2006-5961?

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

Is CVE-2006-5961 being exploited?

CVE-2006-5961 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-2006-5961 affect?

CVE-2006-5961 affects mercury mail transport system. Severity is high (CVSS 7.5). Buffer overflow in Mercury Mail Transport System 4.01b for Windows has unknown impact and attack vectors, as originally reported in a GLEG VulnDisco pack. NOTE: the provenance of this information is unknown; the details are obtained from t

How urgent is CVE-2006-5961?

Priority 52/100. High severity; Public exploit reference

Software pages

Windows vulnerabilities

Related CVEs

CVE-2007-4440 HIGH 7.5 UPGRADE Stack-based buffer overflow in the MercuryS SMTP server in Mercury Mail Transport System, possibly 4.51 and ea
CVE-2007-1373 HIGH 10.0 UPGRADE Stack-based buffer overflow in Mercury/32 (aka Mercury Mail Transport System) 4.01b and earlier allows remote
CVE-2005-4411 HIGH 7.5 DOWNGRADE Buffer overflow in Mercury Mail Transport System 4.01b allows remote attackers to execute arbitrary code via a

References

← Back to latest CVEs