Security readout for executives and security teams
Plain-English summary
This is a high-severity Microsoft Office security feature bypass. Affected Office installations could allow an attacker, with user interaction, to bypass a protection and cause high integrity and availability impact. The provided sources do not describe data theft impact or active exploitation.
Executive priority
Treat as a timely patching priority for Office estates, especially document-heavy teams. The issue is high severity, but current provided evidence does not support emergency active-exploitation handling.
Technical view
CVE-2025-21346 is classified as CWE-693 with CVSS 3.1 score 7.1. Vector indicates local attack, low complexity, no privileges, required user interaction, unchanged scope, no confidentiality impact, and high integrity and availability impact. Microsoft lists an official remediation.
Likely exposure
Organizations using Microsoft 365 Apps for Enterprise, Office 2016, Office 2019, Office LTSC 2021, or Office LTSC 2024 may be exposed if affected versions remain unpatched.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation. CVSS marks exploit code maturity as unproven. User interaction is required, so risk is higher where users routinely open Office files from external or untrusted sources.
Researcher notes
Evidence is limited to public CVE and Microsoft advisory metadata. The bundle does not include technical root cause, bypassed feature details, proof-of-concept evidence, or observed exploitation. Avoid assuming exploitability beyond the CVSS vector.
Mitigation direction
- Apply Microsoft’s official update for affected Office products per the MSRC advisory.
- Inventory Office deployments and identify affected products and versions listed by Microsoft.
- Prioritize patching users who handle external Office documents or high-impact business workflows.
- Check Microsoft guidance for exact update packages, supersedence, and deployment requirements.
Validation and detection
- Confirm affected Office products are present or absent in endpoint inventory.
- Verify installed Office builds are updated according to the MSRC remediation guidance.
- Review patch management reports for failed or deferred Microsoft Office updates.
- Monitor security advisories for any change in exploitation status or mitigation guidance.
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-693: 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-2025-21346 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:N/I:H/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:N/I:H/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:N/I:H/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 Security Feature Bypass 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.
Protection Mechanism Failure
Protection Mechanism Failure represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.