Threats / Microsoft / CVE-2017-0261
CVE-2017-0261
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Microsoft Office vulnerability
Microsoft Office use-after-free vulnerability enabling remote code execution. Actively exploited in the wild with high EPSS score.
Verdict
Today item — known-exploited.
A use-after-free flaw in Microsoft Office allows attackers to execute arbitrary code remotely by crafting malicious documents. The vulnerability has been observed in active exploitation campaigns and poses significant risk to Office users.
01
Is it exploitable?
— the evidence, ranked above the scoreExploit 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
9 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 2022-03-03).
Probability (EPSS)
EPSS 0.7813 — 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-416 Use After Free — 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 that triggers a use-after-free condition when opened.
Business
Users opening untrusted documents face immediate code execution risk without additional user interaction beyond opening the file.
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
Enterprise email and document handling infrastructure becomes a vector for widespread compromise across user populations.
3
Lateral reach — past segmentation narrative 3
Attacker
I gain code execution in the context of the Office application process on the victim's system.
Business
Attackers obtain initial system access with the privileges of the user running Office, enabling lateral movement and data exfiltration.
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