EUVD-2026-56585
GHSA-25v6-4vqg-8444
Severity by source
AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Network-delivered exploit requires user interaction to open crafted content; no authentication needed; integer overflow enabling code execution yields full C/I/A impact.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Lifecycle Timeline
3DescriptionCVE.org
Integer overflow or wraparound in Microsoft Office Outlook allows an unauthorized attacker to execute code over a network.
AnalysisAI
Remote code execution in Microsoft Office Outlook stems from an integer overflow or wraparound condition (CWE-190) that allows an unauthenticated network attacker to execute arbitrary code on a victim's system, achieving full confidentiality, integrity, and availability compromise. The CVSS 3.1 score of 8.8 (High) with vector AV:N/AC:L/PR:N/UI:R reflects low attack complexity and no authentication requirement, though exploitation is gated by a user interaction step. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | The CVSS vector (PR:N, UI:R) confirms exploitation requires no authentication but does require the targeted user to interact with attacker-controlled content - most plausibly opening or previewing a crafted email message, attachment, or embedded object within Microsoft Office Outlook. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 3.1 base score of 8.8 with AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H is a credible rating for this class of vulnerability. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker crafts a malicious email or file attachment engineered to trigger an integer overflow in Outlook's content-parsing routines and delivers it to a target user via a phishing campaign. When the user opens or previews the message in Outlook, the overflow causes an undersized heap allocation, and subsequent data writes corrupt adjacent memory, redirecting execution to attacker-controlled shellcode running under the victim user's credentials. … |
| Remediation | The primary remediation is to apply the Microsoft-issued security update referenced in the MSRC advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70329; an exact patched version number was not confirmed in the available intelligence and must be retrieved directly from the advisory. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, issue a security alert to all Outlook users advising against opening attachments from untrusted senders and clicking embedded links in unsolicited emails; disable or restrict Preview Pane functionality for Outlook to reduce exposure to malicious attachments; and enable attachment sandboxing in your email gateway to isolate potentially malicious files before delivery. …
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Same weakness CWE-190 – Integer Overflow or Wraparound
View allSame technique Integer Overflow
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External POC / Exploit Code
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