VDB-340840 · CVE-2026-20956 · EUVD-2026-2104

Microsoft Excel untrusted pointer dereference

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.
6.1	$0-$5k	0.00

Summaryinfo

A vulnerability labeled as critical has been found in Microsoft Excel. Impacted is an unknown function. Executing a manipulation can lead to untrusted pointer dereference. This vulnerability is registered as CVE-2026-20956. It is possible to launch the attack remotely. No exploit is available. Applying a patch is advised to resolve this issue.

Detailsinfo

A vulnerability classified as critical was found in Microsoft Excel (the affected version unknown). This vulnerability affects an unknown part. The manipulation with an unknown input leads to a untrusted pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-822. The product obtains a value from an untrusted source, converts this value to a pointer, and dereferences the resulting pointer. As an impact it is known to affect confidentiality, integrity, and availability.

The weakness was published 01/13/2026 as confirmed security update guide (Website). The advisory is shared for download at msrc.microsoft.com. This vulnerability was named CVE-2026-20956. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 02/11/2026).

The vulnerability scanner Nessus provides a plugin with the ID 298566 (Security Updates for Microsoft Office Products (February 2026) (macOS)), which helps to determine the existence of the flaw in a target environment.

Applying a patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (298566) and EUVD (EUVD-2026-2104). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Spreadsheet Software

Vendor

Microsoft

Name

Excel

License

commercial

Website

Vendor: https://www.microsoft.com/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.0
VulDB Meta Temp Score: 6.1

VulDB Base Score: 6.3
VulDB Temp Score: 5.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 7.8
Vendor Vector (Microsoft): 🔒

CVSSv2info

AV	AC	Au	C	I	A
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Untrusted pointer dereference
CWE: CWE-822
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔒
Status: Unproven

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 298566
Nessus Name: Security Updates for Microsoft Office Products (February 2026) (macOS)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

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

Timelineinfo

01/13/2026 VulDB entry created
01/13/2026 +0 days Advisory disclosed
01/13/2026 +0 days Countermeasure disclosed
02/11/2026 +29 days VulDB entry last update