Security readout for executives and security teams
Plain-English summary
A flaw in supported Microsoft Office editions can expose sensitive information when a user interacts with malicious content. The attack is local, requires user action, and needs no prior privileges. The supplied CVSS assessment also indicates a potentially serious availability impact.
Executive priority
Treat as a high-priority endpoint remediation item. Accelerate assessment and patching for high-value users and systems, while recognizing that required user interaction and local attack access reduce immediate mass-exploitation risk.
Technical view
CVE-2026-56193 is a CWE-125 out-of-bounds read in Microsoft Office. It has CVSS 3.1 score 7.1: local access, low complexity, no privileges, and required user interaction. The stated impacts are high confidentiality and availability, with no integrity impact.
Likely exposure
Exposure includes the listed Microsoft 365 Apps, Office 2016 and 2019, Office LTSC 2021 and 2024, and corresponding Mac editions. The supplied version entries do not provide complete vulnerable build ranges, so organizations should confirm affected installations through Microsoft guidance.
Exploitation context
The supplied bundle does not establish active exploitation, and the CVE is not identified as CISA KEV. Exploitation requires local access and user interaction, limiting remote automation, but no privileges are required and successful exploitation may disclose sensitive information.
Researcher notes
The record describes an out-of-bounds read but provides no root-cause detail, affected component, attack format, or proof of concept. CVSS includes high availability impact despite the information-disclosure title. Exact vulnerable and fixed build boundaries must be obtained from Microsoft.
Mitigation direction
- Review Microsoft's CVE advisory for product-specific security updates and deployment instructions.
- Prioritize updates for endpoints handling sensitive documents or used by privileged personnel.
- Reduce exposure to untrusted Office files until affected installations are remediated.
- Use existing email and endpoint controls to block or isolate suspicious documents.
Validation and detection
- Inventory installed Office products, platforms, editions, and exact build numbers.
- Compare discovered builds with the current Microsoft advisory's affected and remediated versions.
- Verify applicable security updates installed successfully across Windows and Mac endpoints.
- Monitor endpoint and Office telemetry for suspicious document-triggered crashes or abnormal file access.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-125: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-56193 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H/E:U/RL:O/RC:C
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H/E:U/RL:O/RC:C1.85.2microsoftVulnerability scoring details
Base CVSS 3.1 score
7.1HighVector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H/E:U/RL:O/RC:C
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- Microsoft Office Information Disclosure VulnerabilityCVE reference, microsoft · vendor-advisory, patch
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Out-of-bounds Read
Out-of-bounds Read represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.