CVE-2025-58186

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

State: Published
Severity: 5.3 Medium
Published: Oct 29, 2025
Updated: Nov 4, 2025
Reserved: Aug 27, 2025

Description

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.

Scores

CVSS	Score	Vector	Source
3.1	5.3 Medium	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L	CISA-ADP

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
net/httpGo standard library	before 1.24.8Affected 1.25.0 to before 1.25.2Affected

References

https://go.dev/issue/75672
https://go.dev/cl/709855
https://groups.google.com/g/golang-announce/c/4Emdl2iQ_bI
https://pkg.go.dev/vuln/GO-2025-4012
http://www.openwall.com/lists/oss-security/2025/10/08/1

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