Security readout for executives and security teams
Plain-English summary
A memory-handling flaw in Microsoft Excel can let an attacker run code with the victim’s privileges after required user interaction. Successful exploitation could expose data, alter files, or disrupt the affected system. The supplied CVSS score is 7.8, making this a high-severity issue.
Executive priority
Treat this as a high-priority patching issue because successful exploitation could provide full code execution in a user context. Accelerate remediation for users who routinely receive external spreadsheets and for shared Office services. Emergency incident response is not justified solely by this bundle because active exploitation is not established.
Technical view
CVE-2026-50675 is a heap-based buffer overflow (CWE-122) affecting listed Microsoft Excel and Office products on Windows and macOS, plus Office Online Server. The vector is local, low complexity, requires no privileges, and requires user interaction. Successful exploitation can compromise confidentiality, integrity, and availability without changing security scope.
Likely exposure
Exposure exists where the listed Microsoft 365 Apps, Excel 2016, Office 2019, Office LTSC 2021/2024, Mac editions, or Office Online Server remain affected. Actual exposure depends on installed builds, update status, and whether users process attacker-controlled content. The supplied version labels alone are insufficient for definitive fleet identification.
Exploitation context
The CVSS vector requires user interaction and identifies a local attack vector; the supplied description says an unauthorized attacker can execute code locally. The source bundle does not establish a specific delivery method. This CVE is not listed as KEV in the supplied data, and no cited evidence demonstrates active exploitation.
Researcher notes
The core weakness is CWE-122 heap-based buffer overflow. CVSS 3.1 is 7.8: AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H, with remediation level marked official fix and exploit maturity unproven. The supplied sources do not describe the vulnerable parsing component, triggering file structure, affected build boundaries, or exploitation reliability.
Mitigation direction
- Apply the applicable Microsoft security updates identified in the MSRC advisory.
- Prioritize endpoints handling externally supplied or otherwise untrusted spreadsheet content.
- Use existing controls to restrict untrusted Office content until updates are verified.
- Check Microsoft guidance for product-specific mitigations or prerequisites.
Validation and detection
- Inventory installations of every affected Office and Excel edition listed in the advisory.
- Compare installed builds and update status against Microsoft’s affected-product tables.
- Confirm applicable security updates installed successfully across Windows, macOS, and server assets.
- Review endpoint telemetry for suspicious child processes or unusual activity associated with Excel.
- Retest update compliance after normal deployment and restart procedures.
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-122: 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 lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-50675 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 Remote Code Execution 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.
Heap-based Buffer Overflow
Heap-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.