Vulnerability · Published Oct 29, 2025 · Assigned by Go
CVE-2025-58186Lack of limit when parsing cookies can cause memory exhaustion in net/http
Medium 5.3
In plain English
A medium-severity security flaw in net/http from Go standard library. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 47% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)5.3Medium
Exploit odds (30 days)0.6%top 52.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.22 | go | 1.24.8-r0 | ALPINE-CVE-2025-58186 |
| Alpine:v3.23 | go | 1.25.2-r0 | ALPINE-CVE-2025-58186 |
| Alpine:v3.24 | go | 1.25.2-r0 | ALPINE-CVE-2025-58186 |
| Debian:12 | golang-1.19 | no fix listed | DEBIAN-CVE-2025-58186 |
| Debian:13 | golang-1.24 | no fix listed | DEBIAN-CVE-2025-58186 |
| Go | stdlib | 1.24.8, 1.25.2 | GO-2025-4012 |
| Ubuntu:22.04:LTS | golang-1.17 | no fix listed | UBUNTU-CVE-2025-58186 |
| Ubuntu:22.04:LTS | golang-1.18 | no fix listed | UBUNTU-CVE-2025-58186 |
| Ubuntu:22.04:LTS | golang-1.20 | no fix listed | UBUNTU-CVE-2025-58186 |
| Ubuntu:22.04:LTS | golang-1.21 | no fix listed | UBUNTU-CVE-2025-58186 |
| Ubuntu:24.04:LTS | golang-1.21 | no fix listed | UBUNTU-CVE-2025-58186 |
| Ubuntu:22.04:LTS | golang-1.22 | no fix listed | UBUNTU-CVE-2025-58186 |
| Ubuntu:24.04:LTS | golang-1.22 | no fix listed | UBUNTU-CVE-2025-58186 |
| Ubuntu:22.04:LTS | golang-1.23 | no fix listed | UBUNTU-CVE-2025-58186 |
| Ubuntu:24.04:LTS | golang-1.23 | no fix listed | UBUNTU-CVE-2025-58186 |
| Ubuntu:25.10 | golang-1.23 | no fix listed | UBUNTU-CVE-2025-58186 |
| Ubuntu:26.04:LTS | golang-1.23 | no fix listed | UBUNTU-CVE-2025-58186 |
| Ubuntu:22.04:LTS | golang-1.24 | no fix listed | UBUNTU-CVE-2025-58186 |
| Ubuntu:24.04:LTS | golang-1.24 | no fix listed | UBUNTU-CVE-2025-58186 |
| Ubuntu:25.10 | golang-1.24 | no fix listed | UBUNTU-CVE-2025-58186 |
| Ubuntu:26.04:LTS | golang-1.24 | no fix listed | UBUNTU-CVE-2025-58186 |
| Ubuntu:22.04:LTS | golang-1.25 | no fix listed | UBUNTU-CVE-2025-58186 |
| Ubuntu:24.04:LTS | golang-1.25 | no fix listed | UBUNTU-CVE-2025-58186 |
| Ubuntu:25.10 | golang-1.25 | no fix listed | UBUNTU-CVE-2025-58186 |
| Ubuntu:26.04:LTS | golang-1.25 | no fix listed | UBUNTU-CVE-2025-58186 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Go standard library | net/http | 0 – before 1.24.81.25.0 – before 1.25.2 |