Security readout for executives and security teams
Plain-English summary
This is a high-severity Microsoft Excel issue where a security feature can be bypassed. The sources show affected Microsoft 365 Apps for Enterprise and Office LTSC 2024 versions. Exploitation requires user interaction and has potential high confidentiality, integrity, and availability impact, but the bundle does not prove active exploitation.
Executive priority
Treat as a near-term patching priority for managed Office fleets. It is high impact if exploited, but the provided sources do not show confirmed active exploitation or KEV listing.
Technical view
CVE-2025-21364 is a Microsoft Excel security feature bypass associated with CWE-502. CVSS 3.1 is 7.8: local attack vector, low complexity, no privileges, user interaction required, unchanged scope, and high C/I/A impact. Microsoft provides the vendor advisory and patch reference.
Likely exposure
Organizations using Microsoft 365 Apps for Enterprise 16.0.1 or Microsoft Office LTSC 2024 16.0.0 should treat endpoints with Excel installed as potentially exposed until patched or verified.
Exploitation context
The source bundle lists KEV as false and CVSS exploit maturity as unproven. No cited source in the bundle confirms active exploitation. The attacker model requires local execution conditions and user interaction; the public details provided here do not describe the bypass mechanism.
Researcher notes
Public details in the provided bundle are limited. Key confirmed points are CWE-502, Excel security feature bypass, affected Microsoft Office product lines, CVSS 7.8, user interaction required, and Microsoft patch availability. Do not infer exploitability beyond those signals.
Mitigation direction
- Review Microsoft’s CVE-2025-21364 advisory and apply the listed update.
- Prioritize affected Office and Microsoft 365 Apps deployments in endpoint patching.
- Verify patch rollout through normal software inventory or endpoint management tooling.
- Monitor Microsoft guidance for any revised affected-version or mitigation details.
Validation and detection
- Inventory Microsoft 365 Apps for Enterprise and Office LTSC 2024 installations.
- Compare installed Office versions against Microsoft’s CVE-2025-21364 advisory.
- Confirm endpoints received the relevant Microsoft security update.
- Check vulnerability scanners for closure after patch deployment.
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-502: Code execution behavior lookup
Code execution and unsafe deserialization weaknesses often justify reviewing execution behavior and process telemetry. 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-2025-21364 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
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/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:H/I:H/A:H/E:U/RL:O/RC:C1.85.9microsoftVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/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 Excel 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.
Deserialization of Untrusted Data
Deserialization of Untrusted Data represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.