CVE-2010-0816: Integer overflow in inetcomm.dll in Microsoft Outlook Express 5.5 SP2, 6, and 6 SP1; Windows Live Mail on Wind

This week

HIGH 9.3WATCHLISTDOWNGRADEMITIGATEMITIGATE

CVE-2010-0816 is a high-severity flaw (CVSS 9.3) affecting outlook express, windows live mail, windows mail. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Integer overflow in inetcomm.dll in Microsoft Outlook Express 5.5 SP2, 6, and 6 SP1; Windows Live Mail on Windows XP SP2 and SP3, Windows Vista SP1 and SP2, Windows Server 2008 Gold, SP2, and R2, and Windows 7; and Windows Mail on Windows Vista SP1 and SP2, Windows Server 2008 Gold, SP2, and R2, and Windows 7 allows remote e-mail servers and man-in-the-middle attackers to execute arbitrary code via a crafted (1) POP3 or (2) IMAP response, as demo

Why this priority

Critical severity
EPSS top 3%: very likely to be exploited
Public exploit reference
On your watchlist

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

Risk facts

CVSS score	9.3 (High)
EPSS exploit chance	20.3% (top 3%)
CISA exploited list	No
Weakness	CWE-189
Published	2010-05-12
Last modified	2026-06-16

Publisher (CNA): Microsoft Corporation · Vendor: microsoft

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

Am I affected?

Timeline

2010-05-12 11:46 UTCPublished CVE record published
2026-06-16 23:16 UTCUpdated Record last modified

microsoft outlook express DOWNGRADE

Affected: 5.5 sp2 · 6.0 sp1 · 6.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 5.5

1. Check installed version

apt-cache policy outlook-express || rpm -q outlook-express || outlook-express --version

2. No fixed release: DOWNGRADE to a release before 5.5 (Debian / Ubuntu)

apt-cache madison outlook-express sudo apt install outlook-express=<VERSION_BEFORE_5.5> sudo apt-mark hold outlook-express

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

dnf --showduplicates list outlook-express sudo dnf downgrade outlook-express-<VERSION_BEFORE_5.5> sudo dnf versionlock add outlook-express

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.

microsoft windows live mail MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy windows-live-mail || rpm -q windows-live-mail || windows-live-mail --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

microsoft windows mail MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

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

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

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: Microsoft Windows Outlook Express and Windows Mail - Integer 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-2010-0816?

outlook express: downgrade or apply the listed mitigation; windows live mail: mitigate or apply the listed mitigation; windows mail: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2010-0816 being exploited?

CVE-2010-0816 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-2010-0816 affect?

CVE-2010-0816 affects outlook express, windows live mail, windows mail. Severity is high (CVSS 9.3). Integer overflow in inetcomm.dll in Microsoft Outlook Express 5.5 SP2, 6, and 6 SP1; Windows Live Mail on Windows XP SP2 and SP3, Windows Vista SP1 and SP2, Windows Server 2008 Gold, SP2, and R2, and Windows 7; and Windows Mail on Windows V

How urgent is CVE-2010-0816?

Priority 67/100. Critical severity; EPSS top 3%: very likely to be exploited; Public exploit reference; On your watchlist

Software pages

Windows vulnerabilities · Windows Server vulnerabilities · Outlook vulnerabilities

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References

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