EUVD-2026-56753
GHSA-c5cq-7c9q-gfxq
Severity by source
AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Victim must locally open the crafted file (AV:L, UI:R); attacker needs no credentials (PR:N); only memory read occurs, yielding confidentiality impact only (I:N, A:N).
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
CVSS:3.1/AV:L/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 locally.
AnalysisAI
Out-of-bounds read in Microsoft Excel enables local information disclosure when a user opens a specially crafted spreadsheet. Multiple product lines are affected across Windows and macOS, spanning Excel 2016, Office 2019, LTSC 2021, LTSC 2024, Office 365 for Mac, and Microsoft 365 Apps for Enterprise. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | The victim must actively open a specially crafted Excel file on a system running one of the affected Microsoft Office product versions (UI:R). … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 3.1 base score of 5.5 (Medium) reflects a meaningful but contextually bounded risk. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker crafts a malicious Excel spreadsheet embedding a record structure that triggers an out-of-bounds read in Excel's file parser. The file is distributed to a targeted victim via a phishing email or compromised file-sharing link; upon opening, Excel reads beyond an allocated memory buffer, potentially leaking sensitive contents from the process's address space - such as fragments of other open documents, cached credentials, or application secrets. … |
| Remediation | Apply Microsoft's security update for all affected Office products. … 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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