CVE-2025-47912 Insufficient validation of bracketed IPv6 hostnames in net/url
The Go net/url parser fails to reject non-IPv6 addresses in brackets, potentially allowing security bypasses in applications relying on strict URL validation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-47912?
CVE-2025-47912 is a medium-severity vulnerability in Golang Go, published on 29 Oct 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2025-47912?
2 open source packages ship an affected version, including golang and stdlib. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
golang Bitnami | All versions | 1.24.8, 1.25.2 |
stdlib Go | All versions | 1.24.8, 1.25.2 |
Products include Golang Go.
How do I fix CVE-2025-47912?
Upgrade golang to a fixed version for your release line: 1.24.8 or 1.25.2.
Is CVE-2025-47912 being exploited?
There is no known exploitation of CVE-2025-47912 in the wild and no public exploit code.
Other vulnerabilities in Golang Go
- CVE-2020-0601 Microsoft Windows CryptoAPI Spoofing
- CVE-2026-27143 Missing bound checks can lead to memory corruption in safe Go in cmd/compile
- CVE-2024-24790 Unexpected behavior from Is methods for IPv4-mapped IPv6 addresses in net/netip
- CVE-2023-39320 Arbitrary code execution via go.mod toolchain directive in cmd/go
- CVE-2023-24540 Improper handling of JavaScript whitespace in html/template
Sources
Also known as AZL-78905, AZL-98817, BELL-CVE-2025-47912, BIT-golang-2025-47912, CLEANSTART-2026-AI29486, CLEANSTART-2026-AW80260 and 283 more.