Threats / Microsoft / CVE-2018-0798
CVE-2018-0798
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Microsoft Office vulnerability
Microsoft Office memory corruption vulnerability enabling remote code execution. Exploited in the wild and frequently chained with CVE-2018-0802 for initial compromise.
Verdict
Today item — known-exploited.
Out-of-bounds write in Office object handling permits unauthenticated remote code execution with user-level privileges. High exploitation prevalence and EPSS score indicate active threat. Chaining with CVE-2018-0802 suggests multi-stage attack chains in real-world campaigns.
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
27 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).
Probability (EPSS)
EPSS 0.95121 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Microsoft, Office. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to 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.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution 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 board1
Front door — unauthenticated access narrative 1
Attacker
I craft a malicious Office document exploiting the memory corruption flaw to achieve code execution when opened by a target user.
Business
Employees opening email attachments or downloaded documents face immediate system compromise and data exfiltration risk.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I chain this vulnerability with CVE-2018-0802 to establish persistent access and escalate privileges beyond the initial user context.
Business
Attackers gain foothold for lateral movement across the network and access to sensitive corporate systems and intellectual property.
3
Lateral reach — past segmentation narrative 3
Attacker
I deploy malware or establish command-and-control communication from the compromised Office process.
Business
Organization faces data breach, operational disruption, and potential regulatory compliance violations from uncontrolled system access.
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