Historical catalog analysis: CISA added this entry on February 10, 2026. The entry reflects catalog information retrieved on August 31, 2026, not a snapshot archived on the inclusion date. Check current vendor guidance before acting.
What the vulnerability is
CVE-2026-21514 is a vulnerability in Microsoft Office Word characterized by a reliance on untrusted inputs in a security decision (CWE-807). This flaw could enable an attacker who already has authorized access to the system to elevate their privileges locally.
Exposure and applicability
This vulnerability affects environments deploying Microsoft Office Word. The primary exposure path involves an authorized user or process interacting with the application in a manner that triggers the flawed security decision logic. Because this is a local privilege escalation (LPE) vulnerability, the attacker must already possess some level of access to the target system to attempt the elevation.
Remediation priorities
Based on our analysis, organizations should prioritize remediation based on the criticality of the systems where Microsoft Office Word is installed and the sensitivity of the data accessible via elevated privileges.
Our recommended priority actions include:
1. Vendor Mitigation Deployment: Apply the specific mitigations provided by Microsoft in their security update guide. This is the primary method for reducing exposure.
2. Cloud Service Alignment: For organizations utilizing cloud-based deployments, align remediation efforts with BOD 22-01 guidance as applicable to ensure consistency across hybrid environments.
3. Asset Decommissioning: In scenarios where vendor mitigations are unavailable or cannot be applied due to legacy constraints, the product should be discontinued to eliminate the attack surface.
How to validate remediation
Verification must move beyond simple version checks, as a deployed patch does not always guarantee that the vulnerability is neutralized in the active runtime environment.
Defenders can verify the reduction of exposure by:
* Configuration Audit: Confirming that the specific security updates or configuration changes mandated by the vendor are present and active across all targeted endpoints.
* Privilege Boundary Testing: In a controlled, authorized test environment, verifying that an account with standard user permissions cannot execute actions reserved for higher-privileged accounts via the Word application.
Limits and open questions
There is currently no confirmed data regarding whether this vulnerability has been utilized in known ransomware campaigns. Additionally, while CISA has established a remediation deadline of March 3, 2026, for federal agencies, this date serves as a benchmark rather than a mandatory requirement for non-federal entities.
Residual risk remains if the application is patched but other local vectors exist that allow an attacker to reach the state required to trigger the vulnerability. The effectiveness of any mitigation depends on the successful application of vendor instructions across all affected instances.
Source and editorial note
CVE-2026-21514: Microsoft Office Word Reliance on Untrusted Inputs in a Security Decision Vulnerability · Source date: February 10, 2026 · Retrieved August 31, 2026.
Material facts are tied to the cited primary source. Recommendations are independent defensive analysis unless attributed to the source. Confirm consequential decisions against current authoritative guidance.
Archive date: February 13, 2026. The displayed post date is assigned three days after the source date to organize this retrospective archive; it does not mean this site published the analysis then. First published by this site: September 21, 2026 at 00:06 UTC.
Request a Vulnerability Assessment
Turn security intelligence into action.
Discuss your exposure, priorities, and the evidence needed to validate the outcome.
Request a security assessment ↗