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Threats / Microsoft / CVE-2019-1429
CVE-2019-1429 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Microsoft Internet Explorer vulnerability

Microsoft Internet Explorer memory corruption vulnerability enabling remote code execution with use-after-free and buffer overflow flaws. Actively exploited in the wild.

Verdict

Today item — known-exploited.

A critical memory safety vulnerability in Internet Explorer allows attackers to execute arbitrary code in the user's security context through memory corruption. Active exploitation in the wild elevates risk despite no ransomware association.

CISA KEV Yes · 2021-11-033EPSS 0.72626 (verify live)4
01

Is it exploitable?

— the evidence, ranked above the score
Reported exploitation
4 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.72626 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Microsoft, Internet Explorer. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-416 Use After Free, CWE-787 Out-of-bounds Write — weakness family: Memory safety.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
02

Who’s exploiting it?

— attribution turns risk into urgency
Attribution not established

No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.

03

Why it matters

— the attack path, told twice: adversary, then board
1

Front door — unauthenticated access narrative 1

Attacker
I craft a malicious webpage or email containing specially crafted content that triggers memory corruption when processed by Internet Explorer.
Business
Users visiting untrusted websites or opening malicious emails face immediate code execution risk, compromising endpoint security and data confidentiality.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I exploit the use-after-free and buffer overflow conditions to gain code execution within the browser process running under the victim's user privileges.
Business
Attackers obtain persistent access to user credentials, sensitive files, and internal network resources without requiring additional privilege escalation.
3

Lateral reach — past segmentation narrative 3

Attacker
I establish a foothold on the compromised system to deploy secondary payloads, establish command and control, or move laterally within the network.
Business
Organizations face potential data exfiltration, system compromise, and lateral movement threats across their infrastructure.
04

What to do

— defensible action
  • Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05

Coverage & confidence

— what we know, and what we don’t

Established (cited)

  • KEV listing (CISA)
  • EPSS probability (FIRST)
  • 4 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Catalogued by microsoft (CNA)
  • Coverage gaps — stated, not hidden

  • No EUVD / GCVE mirror in feed — single-authority dependency for the identifier.
  • EPSS & exposure are time-varying; verify live at the source.
  • Threat-actor attribution not established from feed data — absence of a name is not absence of compromise.
  • No finder/reporter credit recorded in the public CVE entry — the work behind this find is unattributed.
  • Disclosure & credit2
    Catalogued by microsoftCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.