CVE-2025-58186: Lack of limit when parsing cookies can cause memory exhaustion in net/http

Published Oct 29, 2025
·
Updated

Despite HTTP headers having a default limit of 1MB, the number of cookies that can be parsed does not have a limit. By sending a lot of very small cookies such as "a=;", an attacker can make an HTTP server allocate a large amount of structs, causing large memory consumption.

Other sources

Lack of limit when parsing cookies can cause memory exhaustion in net/http

Microsoft

Affected Software

16 affected components
Google Go
Microsoft azl3 golang 1.25.3-1
Microsoft azl3 python-tensorboard 2.16.2-6
Microsoft cbl2 python-tensorboard 2.11.0-3
Microsoft cbl2 msft-golang 1.24.8-1
Microsoft cbl2 tensorflow 2.11.1-2
Microsoft cbl2 golang 1.22.7-5
Microsoft azl3 golang 1.23.12-1
Microsoft azl3 tensorflow 2.16.1-9
Microsoft azl3 gcc 13.2.0-7
Microsoft cbl2 golang 1.18.8-10
Microsoft cbl2 gcc 11.2.0-8
Microsoft cbl2 msft-golang 1.24.9-1
Microsoft cbl2 msft-golang 1.24.11-1
Microsoft azl3 golang 1.25.5-1
IBM API Connect V12 OnPrem<=All

Event History

Oct 29, 2025
CVE Published
via MITRE·10:10 PM
Data Sourced
via MITRE·10:10 PM
DescriptionWeakness
Data Sourced
via NVD·11:16 PM
DescriptionSeverity
Oct 31, 2025
Data Sourced
via Microsoft·01:06 AM
DescriptionSeverityWeaknessAffected Software
Updated
via Microsoft·01:06 AM
Affected Software
Updated
via Microsoft·01:06 AM
DescriptionSeverity
Jul 7, 2026
Data Sourced
via IBM·12:00 AM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is the severity of CVE-2025-58186?

CVE-2025-58186 has a high severity level due to its potential to cause significant memory consumption in HTTP servers.

2

How do I fix CVE-2025-58186?

To mitigate CVE-2025-58186, restrict the number of cookies that can be parsed by the HTTP server.

3

What is the impact of exploiting CVE-2025-58186?

Exploiting CVE-2025-58186 can lead to denial of service by exhausting server memory resources.

4

Which software is affected by CVE-2025-58186?

CVE-2025-58186 specifically affects the Google Go programming language.

5

Can CVE-2025-58186 be exploited remotely?

Yes, CVE-2025-58186 can be exploited remotely by sending specially crafted HTTP requests containing numerous small cookies.

Contact

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