Microsoft Exchange Server deserialization

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 (≈)
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CTI Interest Score
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3.3$5k-$25k0.70+

Summaryinfo

A vulnerability described as problematic has been identified in Microsoft Exchange Server. This vulnerability affects unknown code. Executing a manipulation can lead to deserialization. This vulnerability is tracked as CVE-2026-55009. The attack is restricted to local execution. No exploit exists.

Detailsinfo

A vulnerability was found in Microsoft Exchange Server. It has been declared as problematic. This vulnerability affects an unknown code block. The manipulation with an unknown input leads to a deserialization vulnerability. The CWE definition for the vulnerability is CWE-502. The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid. As an impact it is known to affect integrity. CVE summarizes:

Deserialization of untrusted data in Microsoft Exchange Server allows an authorized attacker to elevate privileges locally.

The advisory is available at msrc.microsoft.com. This vulnerability was named CVE-2026-55009 since 06/16/2026. The exploitation appears to be easy. Local access is required to approach this attack. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 07/14/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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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: 3.3
VulDB Meta Temp Score: 3.3

VulDB Base Score: 3.3
VulDB Temp Score: 3.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Deserialization
CWE: CWE-502 / CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

06/16/2026 CVE reserved
07/14/2026 +28 days Advisory disclosed
07/14/2026 +0 days VulDB entry created
07/14/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2026-55009 (🔒)
GCVE (CVE): GCVE-0-2026-55009
GCVE (VulDB): GCVE-100-378502

Entryinfo

Created: 07/14/2026 21:23
Changes: 07/14/2026 21:23 (52)
Complete: 🔍
Cache ID: 216::103

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