CVE-2025-55247Hinoki check available

Build denial via predictable temporary directories

Published Oct 14, 2025 · Updated Oct 14, 2025

Denial of service in the .NET 8.0 and 9.0 SDKs allows local users to interrupt Linux builds through MSBuild's DownloadFile task. MSBuild derives predictable temporary-directory paths, allowing another local user to create those directories before the task and block the build. Only Linux projects that invoke DownloadFile are exposed; the documented consequence is build denial, not privilege elevation.

CVSS severity7.3
High
EPSS probability0.61%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
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Summary

What happened

Denial of service in the .NET 8.0 and 9.0 SDKs allows local users to interrupt Linux builds through MSBuild's DownloadFile task. MSBuild derives predictable temporary-directory paths, allowing another local user to create those directories before the task and block the build. Only Linux projects that invoke DownloadFile are exposed; the documented consequence is build denial, not privilege elevation.

The record

CVE
CVE-2025-55247
Published
Oct 14, 2025
Updated
Oct 14, 2025
Vendor
Microsoft
Product
.NET 9.0
Classifications
CWE-59, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 14, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 14, 2025Record 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.

  1. Affected versionversion=9.0.0 <9.0.10

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft · .NET 9.0version=9.0.0 <9.0.10
Microsoft · .NET 8.0version=8.0.0 <8.0.21

Published CVSS scores

7.3Microsoft CorporationCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-59Improper Link Resolution Before File Access ('Link Following')
T1499.004Application or System Exploitation Abuse

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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