CVE-2025-58186

MEDIUM5.3

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

Published Oct 29, 2025

Modified 2 months ago

No fix available

Details

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.

References

WEBhttp://www.openwall.com/lists/oss-security/2025/10/08/1 WEBhttps://go.dev/cl/709855 WEBhttps://go.dev/issue/75672 WEBhttps://groups.google.com/g/golang-announce/c/4Emdl2iQ_bI WEBhttps://pkg.go.dev/vuln/GO-2025-4012 ADVISORYhttps://www.cve.org/CVERecord?id=CVE-2025-58186

CVSS Analysis

CVSS v3.1

5.3

Exploitability

Attack Vector

NetworkAV:N

Attack Complexity

LowAC:L

Privileges Required

NonePR:N

User Interaction

NoneUI:N

Scope

UnchangedS:U

Impact

Confidentiality

NoneC:N

Integrity

NoneI:N

Availability

LowA:L

5.3/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Ecosystems

Timeline

PublishedOct 29, 2025

ModifiedNov 4, 2025