EUVD-2026-56583
GHSA-2q7m-9rpm-xprw
Severity by source
AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Network-delivered file triggers parsing remotely (AV:N, AC:L, PR:N); victim must open the file (UI:R); impact is read-only memory disclosure with no integrity or availability consequence (C:H/I:N/A:N).
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 Excel exposes sensitive memory contents over a network to unauthenticated remote attackers, resulting in high-confidence information disclosure (C:H). Exploitation requires user interaction - specifically, opening a crafted Excel document - placing this firmly in the phishing/malicious-attachment delivery class. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | The CVSS UI:R metric confirms that exploitation requires the target user to actively open or interact with a malicious Excel file - the vulnerability cannot be triggered without this action. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 6.5 Medium score is driven by AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N: network-exploitable, low complexity, no attacker authentication, but requiring user interaction. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker crafts a malicious Excel spreadsheet containing a specially structured record or formula designed to trigger the out-of-bounds read in Excel's file parser, then delivers it via spearphishing email or a malicious website. When the targeted user opens the file with an unpatched version of Excel, the parser reads beyond the intended buffer boundary, disclosing contents of adjacent heap memory to the attacker - potentially including sensitive in-process data. … |
| Remediation | The primary remediation is to apply the vendor-released patch via Microsoft Update or the Microsoft Update Catalog. … 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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