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Threats / Microsoft / CVE-2025-30397
CVE-2025-30397 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Microsoft Windows vulnerability

Microsoft Windows Scripting Engine type confusion vulnerability allows remote code execution via specially crafted URLs. Actively exploited in the wild.

Verdict

Today item — known-exploited.

Type confusion in the scripting engine permits an attacker to bypass type safety mechanisms and achieve arbitrary code execution on vulnerable Windows systems through network-delivered payloads, with confirmed active exploitation.

CISA KEV Yes · 2025-05-133EPSS 0.21562 (verify live)4Exploit Public PoC5
01

Is it exploitable?

— the evidence, ranked above the score
Exploit available
Public proof-of-concept exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
6 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 2025-05-13).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.21562 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Microsoft, Windows. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-843 Type Confusion — weakness family: Memory safety.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
WeaknessCWE-843 · Type ConfusionMemory safety
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 URL containing specially formatted script content that exploits type confusion in the Windows Scripting Engine.
Business
Users visiting attacker-controlled or compromised websites face immediate risk of system compromise without additional user interaction.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I deliver the URL through email, messaging, or web-based vectors to reach target systems.
Business
Attack surface expands across communication channels, increasing likelihood of successful delivery to target populations.
3

Lateral reach — past segmentation narrative 3

Attacker
I trigger type confusion that causes the scripting engine to misinterpret object types, allowing me to access restricted memory regions or execute arbitrary code.
Business
Attacker gains code execution context with privileges of the affected user or browser process.
4

Data at risk — exfiltration narrative 4

Attacker
I execute arbitrary commands or install malware on the compromised system.
Business
Systems become subject to data theft, lateral movement, persistence mechanisms, or further compromise within the network.
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)
  • Public PoC available (VulnCheck)
  • 6 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Public exploit availability
  • 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.