GO-2025-4010 BIT-golang-2025-47912 CVE-2025-47912
Insufficient validation of bracketed IPv6 hostnames in net/url
- Severity
- 5.3 / 10
- Medium · CVSS 3.1
- Exploit chance (EPSS)
- 0.47%
- Chance of exploitation in the next 30 days. Higher than 40.49% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- —
- Not classified
- Fix
1.25.2- Upgrade stdlib to this version or later
Description
The Parse function permits values other than IPv6 addresses to be included in square brackets within the host component of a URL. RFC 3986 permits IPv6 addresses to be included within the host component, enclosed within square brackets. For example: "http://[::1]/". IPv4 addresses and hostnames must not appear within square brackets. Parse did not enforce this requirement.
Affected versions
Go
| Package | Vulnerable | Fixed in |
|---|---|---|
| stdlib | < 1.24.8>= 1.25.0, < 1.25.2 |
1.24.81.25.2 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
stdlib Go → 1.25.2
- go
go get stdlib@v1.25.2 && go mod tidy
Severity breakdown
CVSS 3.1 5.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
References
Advisories
Fixes and patches
Issue reports
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-4374-p667-p6c8 HTTP/2 rapid reset can cause excessive work in net/http | High Known exploited | Also affects stdlib |
| CVE-2020-0601 Certificate validation bypass on Windows in crypto/x509 | High Known exploited | Also affects stdlib |
| RUSTSEC-2026-0382 Distrust compromised intermediate certificates in crypto/x509 | Medium | Also affects stdlib |
| GO-2026-6613 HTTP/1 server connection desynchronization after 2xx CONNECT response in net/http | High | Also affects stdlib |
| GO-2026-6609 Lack of limit on size of parsed Range headers in net/http | High | Also affects stdlib |
| GO-2026-6608 Memory limit bypass when parsing MIME headers in net/textproto, mime/multipart | High | Also affects stdlib |
| GO-2026-6607 Reject malformed ECH outer extension references in crypto/tls | High | Also affects stdlib |
| GO-2026-6604 Root.Mkdir(All) can follow junctions out of the root on Windows in os | Critical | Also affects stdlib |
Credits: Enze Wang, Jingcheng Yang and Zehui Miao of Tsinghua University
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