Vulnerability

CVE-2009-0556

High· 8.8KEVCVSS8.8EPSS59%

.rules3/5

Microsoft Office PowerPoint Code Injection Vulnerability

Microsoft Office PowerPoint contains a code injection vulnerability that allows remote attackers to execute arbitrary code via a PowerPoint file with an OutlineTextRefAtom containing an invalid index value that triggers memory corruption.

Threat signal

100/100

Severe

Severity

high

CVSS

8.8

EPSS

59%

Active

KEV

CISA KEV — actively exploited

136d overdue

AffectedMicrosoft — Office

Added to KEV

2026-01-07

Federal patch due (BOD 22-01)

2026-01-28

Required action (CISA verbatim)

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Vendor advisory + references

CISA description: “Microsoft Office PowerPoint contains a code injection vulnerability that allows remote attackers to execute arbitrary code via a PowerPoint file with an OutlineTextRefAtom containing an invalid index value that triggers memory corruption.”

CVSS

v3.1Open in FIRST calculator →

8.8/ 10HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Attack VectorNetworkExploitable remotely over the internet — no local access needed.
Attack ComplexityLowNo special conditions — exploit works reliably.
Privileges RequiredNoneUnauthenticated — no credentials needed.
User InteractionRequiredRequires user action (click, file open, etc).
ScopeUnchangedImpact contained to the vulnerable component.
Confidentiality ImpactHighTotal disclosure of sensitive data.
Integrity ImpactHighTotal compromise of integrity — full data modification possible.
Availability ImpactHighTotal loss of availability — full DoS possible.

EPSS

Exploit prediction · 30-day horizonFIRST.org →

59.1%

probability of exploitation in next 30 days

p98

higher than 98% of all CVEs

3-day trend↑ 0pp

Statistically about to be weaponized — top-tier triage urgency.

Vendor VEX

No VEX statements published for CVE-2009-0556. Vendors publish VEX (Vulnerability Exploitability eXchange) to assert per-product whether a CVE is actually exploitable in their distribution.

SSVCAct

Active exploitation with total impact on essential/support systems

exploitation: active
automatable: yes
impact: total
mission: support

Lifecycle

2026-01-07Added to CISA KEVransomware: Unknown
2026-01-07Published
2026-01-28Federal patch due (BOD 22-01)
2026-06-12Last modified1 source

No source-event history recorded yet. New revisions will appear here as ingestors re-fetch this CVE.