Unauthenticated code execution via untrusted-data deserialization
Published Oct 13, 2026 · Updated Oct 13, 2026
Untrusted-data deserialization in Microsoft .NET allows remote attackers to execute code over a network with user interaction. The retrieved Microsoft record does not identify the affected deserializer or explain the faulty operation performed on attacker-controlled input. Exploitation requires user interaction, but the required action and application configuration are not disclosed.
Summary
What happened
Untrusted-data deserialization in Microsoft .NET allows remote attackers to execute code over a network with user interaction. The retrieved Microsoft record does not identify the affected deserializer or explain the faulty operation performed on attacker-controlled input. Exploitation requires user interaction, but the required action and application configuration are not disclosed.
The record
- CVE
- CVE-2026-87697
- Published
- Oct 13, 2026
- Updated
- Oct 13, 2026
- Vendor
- Microsoft Corporation
- Product
- .NET 9.0
- Classifications
- CWE-502
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 13, 2026CVE publishedPublication date reported by the CVE source.
- Oct 13, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=9.0.0 <9.0.21
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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