EUVD-2026-56569
GHSA-vwwc-p79j-c5jm
Severity by source
AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Description confirms only information disclosure; I:H and A:H in official vector are unsubstantiated by the narrative, so assessed at N pending vendor clarification.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
Lifecycle Timeline
3DescriptionCVE.org
Improper input validation in Microsoft Office PowerPoint allows an unauthorized attacker to disclose information locally.
AnalysisAI
PowerPoint's improper input validation (CWE-20) exposes local users to high-impact compromise when a maliciously crafted presentation file is opened, with the official CVSS vector asserting high confidentiality, integrity, and availability impact - a notable divergence from the description's characterization as information disclosure only. The attack requires no attacker privileges but mandates user interaction, fitting a phishing-and-open-file threat model. No public exploit code exists and this vulnerability is not listed in the CISA KEV catalog at time of analysis.
Technical ContextAI
CWE-20 (Improper Input Validation) describes a failure to validate, filter, or sanitize input before it is used in a security-sensitive decision or operation. In a complex file-format parser such as PowerPoint's PPTX/PPT engine, this class of weakness commonly manifests as out-of-bounds reads, heap disclosures, or logic errors triggered by malformed structure entries, embedded objects, or crafted metadata fields. The CVSS vector AV:L/PR:N indicates that no system-level privileges are required, consistent with a scenario where the attacker's only capability is delivering a file that a local user then opens. The S:U scope means impact is contained to the PowerPoint process context. No CPE strings were provided in the intelligence data, so exact affected build numbers cannot be confirmed from this source alone; the vendor advisory at the MSRC reference URL should be consulted for authoritative CPE and version data.
RemediationAI
Consult the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70313 for the official patched version and deployment guidance. No specific fix version number was present in the available intelligence data, so 'Upstream fix available (PR/commit); released patched version not independently confirmed' is the applicable patch status. Apply the relevant Microsoft Office cumulative update or security patch via Windows Update, Microsoft Update Catalog, or your enterprise patch management platform (WSUS, MECM/SCCM, Intune). As a compensating control while patching is in progress, configure Microsoft Defender's Protected View or Attack Surface Reduction rules to force all externally-sourced Office files to open in read-only/sandboxed mode, preventing macro and content execution; note this may break legitimate workflows that depend on editing emailed documents. Additionally, restrict users from opening PowerPoint files received from untrusted external sources outside of a sandboxed viewer environment.
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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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