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Threats / Microsoft / CVE-2023-36563
CVE-2023-36563 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Microsoft WordPad vulnerability

Microsoft WordPad contains an input validation vulnerability allowing information disclosure. The flaw has been exploited in the wild.

Verdict

Today item — known-exploited.

An unspecified input validation flaw in WordPad enables attackers to extract sensitive information from affected systems. Active exploitation in the wild indicates immediate risk to users who open untrusted documents.

CISA KEV Yes · 2023-10-103EPSS 0.20879 (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 2023-10-10).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.20879 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Microsoft, WordPad. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-20 Improper Input Validation.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 WordPad document with invalid input that bypasses validation checks.
Business
Users unknowingly open documents that expose confidential data, creating compliance and privacy breach risks.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I distribute the weaponized document via email or file-sharing platforms to target organizations.
Business
Information disclosure incidents damage customer trust and trigger regulatory notification obligations.
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.