EUVD-2026-56580
GHSA-f56g-8wr8-98q6
Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Local delivery of crafted document required (AV:L); victim must open it (UI:R); no system privileges needed; only confidentiality impacted, no integrity or availability effect.
Primary rating from NVD.
CVSS VectorNVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Lifecycle Timeline
3DescriptionNVD
Improper input validation in Microsoft Office allows an unauthorized attacker to disclose information locally.
AnalysisAI
Information disclosure in Microsoft Office (spanning 365 Apps for Enterprise, LTSC 2021/2024, Office 2019, and macOS variants) is triggered locally when a user opens a specially crafted document, exploiting improper input validation (CWE-20) to expose sensitive information with high confidentiality impact. The CVSS 3.1 vector (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N, score 5.5) confirms local-only exploitation requiring user interaction, substantially limiting opportunistic mass exploitation. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires that the victim have a vulnerable version of Microsoft Office installed (any of the seven affected product lines listed in EUVD data) and that the victim actively open a specially crafted Office document - user interaction (UI:R) is a hard prerequisite. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 3.1 score of 5.5 (Medium) accurately reflects the constrained exploitation conditions: AV:L limits attackers to local delivery of a malicious file, AC:L indicates no special timing or configuration race required once the file is delivered, PR:N means no account privileges are needed to stage the attack, and UI:R introduces a mandatory dependency on victim action. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker crafts a malicious Office document and delivers it to a target user via phishing email, shared network drive, or removable media. When the user opens the document - satisfying the required user interaction - the improper input validation flaw is triggered within the local Office process, causing sensitive information (such as in-memory data or accessible file content) to be disclosed to the attacker. … |
| Remediation | Apply the vendor-released patch immediately via Microsoft Update or the Office deployment tooling in use. … Detailed patch versions, workarounds, and compensating controls in full report. |
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Same weakness CWE-20 – Improper Input Validation
View allSame technique Information Disclosure
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External POC / Exploit Code
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