How severe is CVE-2016-3366?

CVE-2016-3366 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2016-3366 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 16% (97th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-3366?

CVE-2016-3366 primarily affects Microsoft Outlook. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-3366?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2016-3366 published?

CVE-2016-3366 was published on 2016-09-14 and last updated on 2026-06-17.

CVE-2016-3366

CVE-2016-3366 is a medium-severity vulnerability in Microsoft Outlook with a CVSS 3.x base score of 6.5. Its EPSS exploit-prediction score of 16% places it in the 97th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-284.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.3
EPSS exploit prediction: 16% (97th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-284
Affected product: Microsoft Outlook
Published: 2016-09-14
Last modified: 2026-06-17

Description

Microsoft Outlook 2007 SP3, Outlook 2010 SP2, Outlook 2013 SP1, Outlook 2013 RT SP1, Outlook 2016, and Outlook 2016 for Mac do not properly implement RFC 2046, which allows remote attackers to bypass virus or spam detection via crafted MIME data in an e-mail attachment, aka "Microsoft Office Spoofing Vulnerability."

Frequently asked questions

What is CVE-2016-3366?: Microsoft Outlook 2007 SP3, Outlook 2010 SP2, Outlook 2013 SP1, Outlook 2013 RT SP1, Outlook 2016, and Outlook 2016 for Mac do not properly implement RFC 2046, which allows remote attackers to bypass virus or spam detection via crafted MIME data in an e-mail attachment, aka "Microsoft Office Spoofing Vulnerability."
How severe is CVE-2016-3366?: CVE-2016-3366 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2016-3366 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 16% (97th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-3366?: CVE-2016-3366 primarily affects Microsoft Outlook. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-3366?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2016-3366 published?: CVE-2016-3366 was published on 2016-09-14 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:microsoft:outlook:2007:sp3:*:*:*:*:*:*
cpe:2.3:a:microsoft:outlook:2010:sp2:*:*:*:*:*:*
cpe:2.3:a:microsoft:outlook:2013:sp1:*:*:*:*:*:*
cpe:2.3:a:microsoft:outlook:2016:*:*:*:*:macos:*:*

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