CVE-2026-55049

Status: AnalyzedHigh (7.8)—

Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.

CVSS

Version: 3.1
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Base score: 7.8

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 0.47%
Percentile among all scored CVEs: 38
Score date: 10/4/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

🎯 ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

ExploitationT1203 Exploitation for Client Executionexecution95 %
Primary impactT1059 Command and Scripting Interpreterexecution90 %

AV:L + UI:R indica ejecución en cliente (abrir archivo de Office preparado). CWE-122 (buffer overflow en heap) en Office permite ejecución de código arbitrario. T1203 por requerer interacción del usuario al abrir documento malicioso.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

🛡️ ATT&CK mitigations that cover these techniques

Restrict Web-Based Content Privileged Account Management Limit Software Installation Execution Prevention Behavior Prevention on Endpoint Disable or Remove Feature or Program

Affected technologies (5)

Microsoft — 365 Apps Microsoft — Office 2016 Microsoft — Office 2019 Microsoft — Office 2021 Microsoft — Office 2024

CWEs

CWE-122

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55049

Raw JSON (NVD)

Show

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