Security readout for executives and security teams
Plain-English summary
A flaw in how Microsoft Office searches for code could let an attacker run unauthorized code after a user interacts with attacker-influenced content or context. Successful exploitation could compromise sensitive data, alter systems, or disrupt availability. The supplied evidence rates it high severity but indicates exploitation is difficult and requires user interaction.
Executive priority
Treat this as a high-priority patching and exposure-management item, especially on systems handling sensitive information or critical collaboration services. It is not supported as an emergency active-exploitation event, but successful compromise could have broad business impact. Require prompt inventory, vendor-guided updating, and documented verification.
Technical view
CVE-2026-20943 is a CWE-426 untrusted search path vulnerability affecting listed Microsoft Office, Office Deployment Tool, and SharePoint products. CVSS 3.1 is 7.0: local access, high complexity, no privileges, and user interaction required, with high confidentiality, integrity, and availability impact. Despite the remote-code-execution title, the supplied vector is AV:L.
Likely exposure
Potential exposure exists where the listed Office 2016, Office Deployment Tool, SharePoint Enterprise Server 2016, SharePoint Server 2019, or SharePoint Server Subscription Edition versions are deployed. The bundle does not provide fixed build numbers, configuration prerequisites, or sufficient detail to determine whether every installation is exploitable.
Exploitation context
The source bundle does not establish active exploitation, and the CVE is not identified as being in KEV. Exploitation requires user interaction and high attack complexity according to the CVSS vector. No public exploit availability or observed attack activity is established by the supplied evidence.
Researcher notes
The available evidence identifies CWE-426 but does not describe the vulnerable search order, triggering component, attacker-controlled location, fixed builds, or practical exploit reliability. The affected-product list spans endpoint and server products, so assumptions should not be generalized across them. Consult Microsoft’s advisory for product-specific applicability and remediation details.
Mitigation direction
- Review Microsoft’s CVE advisory for affected and fixed build details.
- Deploy the applicable Microsoft security updates through established change controls.
- Inventory the listed Office, Deployment Tool, and SharePoint products across endpoints and servers.
- Apply Microsoft-recommended mitigations if patching must be delayed.
- Increase monitoring for unexpected code execution involving affected products.
Validation and detection
- Compare installed product builds with Microsoft’s current affected and fixed version tables.
- Confirm security updates completed successfully across managed endpoints and SharePoint servers.
- Re-scan assets after remediation and investigate remaining vulnerable detections.
- Verify update coverage includes disconnected, remote, and rarely used systems.
- Review security telemetry for unexpected child processes or code loading involving affected products.
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-426: 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-2026-20943 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 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:H/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:H/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C15.9microsoftVulnerability scoring details
Base CVSS 3.1 score
7HighVector: CVSS:3.1/AV:L/AC:H/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 Click-To-Run 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.
Untrusted Search Path
Untrusted Search Path represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.