Office
CVE-2026-21261
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2021 - Vulnerable and Outdated Components
ASVS 5.0
V15 - Secure Coding and Architecture Bounds checking, read limits
MITRE ATT&CK
1 technique across 1 tactic: Collection The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS 5.5 (MEDIUM). Attack vector: Local. Complexity: Low. Privileges required: None. User interaction: Required. Exploitation no authentication required. Exploitable via local access. |
| Exploit ScenarioDerived | An attacker without authentication could exploit this vulnerability to compromise the affected system. |
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Alert meAnalysisAIv1 – Mar 12, 2026
Information disclosure in Microsoft Office Excel and related products results from an out-of-bounds read vulnerability that requires local access and user interaction to exploit. An attacker can leverage this flaw to read sensitive data from memory on an affected system. No patch is currently available for this vulnerability affecting Office Long Term Servicing Channel, 365 Apps, and Office Online Server.
Earlier versions of this analysis (1)
Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information locally. [CVSS 5.5 MEDIUM]
RemediationAI
Monitor vendor advisories for a patch.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 9 packages in microsoft
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
Classified as CWE-125 (Out-of-bounds Read). Affects 365 Apps. Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionCVE.org
Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.
Executive ViewAI
Organizations using Out-of-bounds read in Microsoft Office Excel should be aware of moderate risk from CVE-2026-21261, a out-of-bounds read vulnerability rated CVSS 5.5. Exploitation could cause memory corruption or application crashes. Organizations should apply vendor updates when available and monitor for exploitation.
Apply vendor patch. If patching is delayed: enable ASLR/DEP, apply network segmentation.
Threat Intelligence Overview
NVD
CVE.org
EPSS
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Affected Products (CPE)CVE.org
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Microsoft Word Remote Code Execution Vulnerability. Rated critical severity (CVSS 9.8), this vulnerability is remotely e
Microsoft SharePoint Server 2007 SP3, 2010 SP1 and SP2, and 2013; Office Web Apps 2010; Excel 2003 SP3, 2007 SP3, 2010 S
The font library in Microsoft Windows Vista SP2; Windows Server 2008 SP2 and R2 SP1; Windows 7 SP1; Windows 8.1; Windows
Microsoft Word 2007 SP3, Office 2010 SP2, Word 2010 SP2, Word 2013 SP1, Word 2013 RT SP1, Office for Mac 2011, Office fo
Microsoft Word 2007 SP3, Office 2010 SP2, Word 2010 SP2, Word Automation Services in SharePoint Server 2010, Web Applica
Buffer overflow in the Adobe Type Manager Library in Microsoft Windows Vista SP2, Windows Server 2008 SP2, Office 2007 S
Microsoft Word 2007 SP3, Office 2010 SP2, Word 2010 SP2, and Office for Mac 2011 allow remote attackers to execute arbit
Microsoft Office 2007 SP3 allows remote attackers to execute arbitrary code via a crafted document, aka "Microsoft Offic
Integer underflow in Microsoft Office 2007 SP3, Office 2010 SP2, Office 2013 SP1, Office 2013 RT SP1, Office for Mac 201
Microsoft Office 2007 SP3 and 2010 SP2, Live Meeting 2007 Console, Lync 2010, Lync 2010 Attendee, Lync 2013 SP1, and Lyn
Microsoft Excel Security Feature Bypass Vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no authenti
GitHub PoC
Exploit-DB