What is the CVSS score of CVE-2026-68793?

CVE-2026-68793 has a CVSS 3.1 base score of 7.8 (High). CVSS vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.3%.

Which versions of Microsoft Excel are affected by CVE-2026-68793?

Microsoft Office Excel contains a high-severity vulnerability (CVE-2026-68793) enabling code execution when users open specially crafted workbook files, potentially granting attackers full system…. A patch is available.

How to fix or mitigate CVE-2026-68793?

Within 24 hours: Implement email gateway controls to block or quarantine .xlsx and .xls attachments from external senders, and alert employees to avoid opening untrusted workbook files. Within 7 days: Deploy or enhance endpoint detection and response (EDR) to monitor for anomalous Excel process behavior, implement Group Policy to disable Excel macros across the organization unless business-critical, and conduct security awareness training on file-based attack risks. Within 30 days: Implement application sandboxing (e.g., Windows Defender Application Guard) for Excel processes, establish automated antivirus scanning for all incoming Office documents, create a rapid patch-deployment plan with pre-configured test environments for CVE-2026-68793, and establish automated monitoring of Microsoft security advisories for patch release with immediate deployment upon availability.

Microsoft Excel CVE-2026-68793

EUVD-2026-56452 HIGH

Out-of-bounds Read (CWE-125)

2026-08-11 secure@microsoft.com

GHSA-45m5-pvjg-v496

Buffer Overflow Information Disclosure Microsoft 365 Apps Excel Microsoft 365 Office 2021 Office 2024 Office 2019

7.8

CVSS 3.1 · Vendor: microsoft

Severity by source

Vendor (microsoft) PRIMARY

7.8 HIGH

AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

vuln.today AI

7.8 HIGH

File-parsing flaw requires local file open (AV:L, UI:R); no attacker privileges needed (PR:N); full process compromise achievable (C:H/I:H/A:H); scope unchanged (S:U).

3.1 AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

4.0 AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (microsoft).

CVSS VectorVendor: microsoft

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Patch available

Aug 11, 2026 - 18:19 EUVD

Analysis Generated

Aug 11, 2026 - 18:10 vuln.today

CVE Published

Aug 11, 2026 - 17:19 nvd

HIGH 7.8

DescriptionCVE.org

Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to execute code locally.

AnalysisAI

Out-of-bounds read in Microsoft Office Excel enables local code execution when a user opens a specially crafted workbook file. The CVSS vector (AV:L/AC:L/PR:N/UI:R) confirms file-based delivery requiring victim interaction, achieving full confidentiality, integrity, and availability impact on the compromised host. No public exploit code has been identified at time of analysis, and the vulnerability is not listed in the CISA KEV catalog.

Technical ContextAI

CWE-125 (Out-of-bounds Read) describes a condition where software reads data past the end of an allocated buffer during file parsing. In Excel's case, the parser processes attacker-controlled file structures - likely a malformed cell record, formula token, or drawing object within an .xls/.xlsx container - without adequately validating the read boundary. The tags flag both 'Information Disclosure' and 'Buffer Overflow', suggesting the out-of-bounds read exposes adjacent memory contents that can also be weaponized to redirect execution flow, consistent with achieving code execution as described. The local attack vector (AV:L) with user interaction (UI:R) confirms this is a file-parsing vulnerability triggered when a user opens a malicious document, not a network-reachable endpoint.

RemediationAI

Apply the Microsoft security update addressing CVE-2026-68793 as published in the MSRC update guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-68793. No specific fixed build number is available in the current data set - consult the advisory directly for the exact patch version. If immediate patching is not possible, a compensating control is to configure Microsoft Office Protected View to open all externally sourced documents in read-only sandboxed mode, which prevents automatic macro and object execution and reduces the attack surface for file-parsing flaws; note this may interrupt workflows that rely on active editing of downloaded files. Additionally, deploying Attack Surface Reduction (ASR) rules via Microsoft Defender for Endpoint to block Office applications from creating child processes provides an additional layer of defense against code execution payloads.