EUVD-2026-56584
GHSA-w8qr-fj2w-hvr6
Severity by source
AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
File-borne delivery requires user interaction (UI:R); no attacker authentication needed; impact is confidentiality-only with no integrity or availability consequence.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Lifecycle Timeline
3DescriptionCVE.org
Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information over a network.
AnalysisAI
Out-of-bounds read in Microsoft Office Excel enables remote information disclosure when a user opens a specially crafted spreadsheet. The CVSS vector (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N) confirms that an unauthenticated network-based attacker can trigger the flaw, but only after social engineering a victim into opening a malicious file. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | User must actively open a specially crafted Excel file delivered by the attacker - confirmed by CVSS UI:R. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS base score of 6.5 appropriately reflects a meaningful but bounded risk: network delivery and low attack complexity are offset by the mandatory user interaction (UI:R), which prevents fully automated exploitation. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker crafts a malicious Excel spreadsheet and delivers it via phishing email or a compromised web download. When a user on an unpatched Office installation opens the file, the Excel parser triggers an out-of-bounds read, potentially leaking in-memory content - such as document data, tokens, or other sensitive material - back to attacker-controlled infrastructure. … |
| Remediation | Apply the vendor-released patch immediately via Microsoft Update or the Office update mechanism. … Detailed patch versions, workarounds, and compensating controls in full report. |
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Same weakness CWE-125 – Out-of-bounds Read
View allSame technique Information Disclosure
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External POC / Exploit Code
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