Medium severity · published Oct 29, 2025
CVE-2025-58186
Lack of limit when parsing cookies can cause memory exhaustion in net/http
5.3
CVSS
0.6%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 47% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NE
net/http · Go standard library
before 1.24.8; 1.25.0 before 1.25.2 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-58186
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-58186
go.dev
https://go.dev/cl/709855
go.dev
https://go.dev/issue/75672
groups.google.com
https://groups.google.com/g/golang-announce/c/4Emdl2iQ_bI
pkg.go.dev
https://pkg.go.dev/vuln/GO-2025-4012
www.openwall.com
http://www.openwall.com/lists/oss-security/2025/10/08/1
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