CVE-2016-3298: Microsoft Internet Explorer Messaging API Information Disclosure Vulnerability
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on 24 May 2022, 2,048 days after the CVE record was published.
- How likely is exploitation in the next 30 days?
- 33.3%
EPSS score, percentile 98.4 of all scored records
- How severe?
- 6.5 Medium
CVSS v3.1 base score, from CISA's enrichment of the record
- What should I do?
CISA deadline 14 Jun 2022. Apply updates per vendor instructions.
- Which versions are affected?
Not stated. The CVE record gives vendor and product as “n/a” and the version as “unspecified”.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
What to do
Required action, set by CISA
Apply updates per vendor instructions.
CISA due date for this action: 14 June 2022.
Advisories and patches
Linked from CISA's catalog entry
Affected products and versions
The CVE record does not name affected products or versions: vendor and product are “n/a” and the version is “unspecified”.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
About this vulnerability
An information disclosure vulnerability exists when the Microsoft Internet Messaging API improperly handles objects in memory. An attacker who successfully exploited this vulnerability could allow the attacker to test for the presence of files on disk.
Summary: CISA's KEV catalog, as of 28 Oct 2026.
- CISA added CVE-2016-3298 to its Known Exploited Vulnerabilities (KEV) catalog on 24 May 2022.
- CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
- The due date CISA sets for the required action is 14 Jun 2022.
- The CVE record was published on 14 Oct 2016, 2,048 days before it was added to KEV.
- The CVE record carries a CVSS v3.1 base score of 6.5 (Medium), taken from CISA's enrichment of the record.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 33.3% (percentile 98.4), as of 28 Oct 2026.
- CISA's SSVC assessment in the CVE record: exploitation active, automatable no, technical impact partial.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026. About the data.
Description
Microsoft Internet Explorer 9 through 11 and the Internet Messaging API in Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, and Windows 7 SP1 allow remote attackers to determine the existence of arbitrary files via a crafted web site, aka "Internet Explorer Information Disclosure Vulnerability."
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
Weakness
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.
Timeline
| Date | Event |
|---|---|
| 14 Oct 2016 | CVE record published |
| 24 May 2022 | Added to CISA KEV |
| 14 Jun 2022 | CISA due date for the required action |
| 21 Oct 2025 | CVE record last updated |
References
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