Security readout for executives and security teams
Plain-English summary
A flaw in affected Microsoft Office and related server products could let an unauthenticated attacker run code after a user interacts with attacker-controlled input. Successful exploitation could expose data, alter systems, or interrupt operations. The supplied evidence rates it high severity, not critical.
Executive priority
Treat as a prompt patching priority because exploitation could compromise data and system integrity without prior privileges. Focus first on broadly deployed Office endpoints and affected collaboration servers. Escalate urgency if internal telemetry or later authoritative reporting indicates exploitation.
Technical view
CVE-2025-26642 is an out-of-bounds read associated with CWE-125 and CWE-190. It has CVSS 3.1 score 7.8: local attack vector, low complexity, no privileges, required user interaction, unchanged scope, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure applies to organizations running the listed Microsoft 365 Apps, Access, Excel, Office, Office LTSC, SharePoint Server 2019, or Office Online Server versions without the applicable Microsoft security update. The supplied version labels alone are insufficient to determine whether an individual installation is patched.
Exploitation context
The supplied bundle does not identify this CVE as CISA KEV-listed or provide evidence of active exploitation. Exploitation requires user interaction and results in local code execution; the available evidence does not describe the precise delivery method or exploitation chain.
Researcher notes
The record links an out-of-bounds read with integer-overflow classification, but the supplied sources do not explain the vulnerable component, trigger format, memory-corruption path, or exact fixed builds. Validation should rely on Microsoft's advisory and installed update state, not only the generic version identifiers supplied.
Mitigation direction
- Apply the applicable security updates identified in Microsoft's CVE advisory.
- Prioritize affected user endpoints and exposed SharePoint or Office Online Server deployments.
- Use existing controls to limit interaction with untrusted Office content pending updates.
- Consult Microsoft guidance for product-specific update and mitigation requirements.
Validation and detection
- Inventory installations of every product listed in the Microsoft advisory.
- Compare installed builds and update status against Microsoft's current CVE guidance.
- Confirm required security updates deployed successfully across endpoints and servers.
- Review security telemetry for suspicious Office-related code execution or abnormal child processes.
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 lookupCWE-190: 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-2025-26642 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 Office 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.
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.
Integer Overflow or Wraparound
Integer Overflow or Wraparound represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.