CVE-2006-5270: Integer overflow in the Microsoft Malware Protection Engine (mpengine.dll), as used by Windows Live OneCare, A

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HIGH 9.3WATCHLISTMITIGATEMITIGATEMITIGATE

CVE-2006-5270 is a high-severity flaw (CVSS 9.3) affecting antigen, forefront security, malware protection engine. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Integer overflow in the Microsoft Malware Protection Engine (mpengine.dll), as used by Windows Live OneCare, Antigen, Defender, and Forefront Security, allows user-assisted remote attackers to execute arbitrary code via a crafted PDF file.

Why this priority

Critical severity
EPSS top 2%: very likely to be exploited
On your watchlist

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

Risk facts

CVSS score	9.3 (High)
EPSS exploit chance	30.3% (top 2%)
CISA exploited list	No
Published	2007-02-13
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: microsoft

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

Am I affected?

Timeline

2007-02-13 20:28 UTCPublished CVE record published
2026-06-16 22:30 UTCUpdated Record last modified

microsoft antigen 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 antigen || rpm -q antigen || antigen --version

No fixed or unaffected release known

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

microsoft forefront security 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 forefront-security || rpm -q forefront-security || forefront-security --version

No fixed or unaffected release known

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

microsoft malware protection engine 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 malware-protection-engine || rpm -q malware-protection-engine || malware-protection-engine --version

No fixed or unaffected release known

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

microsoft windows defender 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-defender || rpm -q windows-defender || windows-defender --version

No fixed or unaffected release known

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

microsoft windows live onecare 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-onecare || rpm -q windows-live-onecare || windows-live-onecare --version

No fixed or unaffected release known

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

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-2006-5270?

antigen: mitigate or apply the listed mitigation; forefront security: mitigate or apply the listed mitigation; malware protection engine: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2006-5270 being exploited?

CVE-2006-5270 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-2006-5270 affect?

CVE-2006-5270 affects antigen, forefront security, malware protection engine. Severity is high (CVSS 9.3). Integer overflow in the Microsoft Malware Protection Engine (mpengine.dll), as used by Windows Live OneCare, Antigen, Defender, and Forefront Security, allows user-assisted remote attackers to execute arbitrary code via a crafted PDF file.

How urgent is CVE-2006-5270?

Priority 62/100. Critical severity; EPSS top 2%: very likely to be exploited; On your watchlist

Software pages

Windows vulnerabilities · Windows Defender vulnerabilities

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References

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