CVE-2016-3298
CVE-2016-3298 is a security flaw in Microsoft Internet Explorer, Microsoft’s old web browser, still built into Windows. Attackers can read information from Microsoft Internet Explorer that should be private. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 24 May 2022.[1]
Microsoft Internet Explorer is in things households have, such as phones, computers, browsers and everyday apps, so the fix matters at home as much as at work. Microsoft has published a fix or advice.
Description
CISA calls it a messaging API information disclosure in Microsoft Internet Explorer. In its words: “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.”[1]
The CVE record adds: “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."”[2]
The underlying weakness is information exposure (CWE-200), in MITRE’s list of common software weaknesses.
It scores 6.5 out of 10 on the Common Vulnerability Scoring System, which rates it medium, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it; Microsoft’s advisory has them[3]. CISA names the product as Microsoft Internet Explorer.
Every device with Microsoft Internet Explorer needs the update.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 24 May 2022, 2,048 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 14 Jun 2022 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 33%. That’s in the top 2% of the flaws it scores.[4]
CISA assesses it as not automatable: each attack takes some work.
CISA doesn’t say who was attacked, or how.
Fix
Microsoft has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]
- Update Microsoft Internet Explorer now.Install the latest update from Microsoft on every device that has it, and restart when asked. Then turn on automatic updates, so the next fix arrives on its own.
- If there’s no update, stop using it.CISA’s advice when a flaw being used in attacks has no fix is to stop using the product until it does.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 6.5.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 33%.[4] |
See also
Other Microsoft Internet Explorer flaws
- CVE-2010-0806: use-after-free ·
- CVE-2010-0249: use-after-free ·
- CVE-2010-3962: uninitialized memory corruption ·
- CVE-2013-3893: resource management errors ·
- CVE-2012-4792: use-after-free ·
- CVE-2013-3163: memory corruption ·
Other Microsoft flaws
- CVE-2026-96951, Microsoft Windows: command injection ·
- CVE-2026-65660, Microsoft SharePoint: code injection ·
- CVE-2026-85880, Microsoft Windows: heap-based buffer overflow ·
- CVE-2026-81963, Microsoft Windows: link following ·
- CVE-2019-1068, Microsoft SQL Server: remote code execution ·
Other information exposure flaws
- CVE-2025-68686, Fortinet FortiOS: exposure of sensitive information to an unauthorized actor ·
- CVE-2026-20133, Cisco Catalyst SD-WAN Manager: exposure of sensitive information to an unauthorized actor ·
- CVE-2025-31125, Vitejs: improper access control ·
- CVE-2021-41277, Metabase: geoJSON API local file inclusion ·
- CVE-2024-24919, Check Point Quantum Security Gateways: information disclosure ·
Added the same day
- CVE-2018-8611, Microsoft Windows: kernel privilege escalation ·
- CVE-2018-19953, QNAP Network Attached Storage (NAS): NAS file station cross-site scripting ·
- CVE-2018-19949, QNAP Network Attached Storage (NAS): NAS file station command injection ·
- CVE-2018-19943, QNAP Network Attached Storage (NAS): NAS file station cross-site scripting ·
- CVE-2017-8543, Microsoft Windows: search remote code execution ·
Every Microsoft flaw on CISA’s list · Everything added in May 2022
References
- ^ Cybersecurity and Infrastructure Security Agency. “Microsoft Internet Explorer Messaging API Information Disclosure Vulnerability”. Known Exploited Vulnerabilities Catalog, added 24 May 2022.
- ^ National Institute of Standards and Technology. “CVE-2016-3298 Detail”. National Vulnerability Database, published 14 Oct 2016.
- ^ Microsoft. Advisories and fixes: docs.microsoft.com, docs.microsoft.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.333, percentile 98.4, 31 Oct 2026.
- CVE Program. “CVE-2016-3298”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.