Microsoft Excel up to Office Online Server race condition

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.2$0-$5k0.00-

Summaryinfo

A vulnerability described as problematic has been identified in Microsoft Excel up to Office Online Server. Affected is an unknown function. The manipulation results in race condition. This vulnerability is cataloged as CVE-2026-44818. The attack may be launched remotely. There is no exploit available. It is best practice to apply a patch to resolve this issue.

Detailsinfo

A vulnerability was found in Microsoft Excel up to Office Online Server. It has been classified as problematic. Affected is an unknown code block. The manipulation with an unknown input leads to a race condition vulnerability. CWE is classifying the issue as CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. This is going to have an impact on confidentiality, integrity, and availability.

The weakness was shared 06/09/2026 as confirmed security update guide (Website). The advisory is available at msrc.microsoft.com. This vulnerability is traded as CVE-2026-44818. The exploitability is told to be difficult. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 06/09/2026).

Upgrading to version 10.0.17763.8880 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The best possible mitigation is suggested to be patching the affected component. A possible mitigation has been published immediately after the disclosure of the vulnerability.

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Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.0
VulDB Meta Temp Score: 5.2

VulDB Base Score: 5.0
VulDB Temp Score: 4.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 7.0
Vendor Vector (Microsoft): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Race condition
CWE: CWE-362
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔒
Status: Unproven
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

Reaction Time: 🔒
0-Day Time: 🔒
Exposure Time: 🔒

Upgrade: Excel 10.0.17763.8880

Timelineinfo

06/09/2026 VulDB entry created
06/09/2026 +0 days Advisory disclosed
06/09/2026 +0 days Countermeasure disclosed
06/09/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2026-44818 (🔒)
GCVE (CVE): GCVE-0-2026-44818
GCVE (VulDB): GCVE-100-369654

Entryinfo

Created: 06/09/2026 19:45
Updated: 06/09/2026 19:48
Changes: 06/09/2026 19:45 (32), 06/09/2026 19:48 (37)
Complete: 🔍
Cache ID: 216::103

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