Vulnerability · Published Dec 3, 2025 · Assigned by Go
CVE-2025-61727Improper application of excluded DNS name constraints when verifying wildcard names in crypto/x509
Medium 6.5
In plain English
A medium-severity security flaw in crypto/x509 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 0.3% (higher than 23% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.3%top 76.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
An excluded subdomain constraint in a certificate chain does not restrict the usage of wildcard SANs in the leaf certificate. For example a constraint that excludes the subdomain test.example.com does not prevent a leaf certificate from claiming the SAN *.example.com.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.23 | docker | 29.1.2-r0 | ALPINE-CVE-2025-61727 |
| Alpine:v3.24 | docker | 29.1.2-r0 | ALPINE-CVE-2025-61727 |
| Alpine:v3.22 | go | 1.24.11-r0 | ALPINE-CVE-2025-61727 |
| Alpine:v3.23 | go | 1.25.5-r0 | ALPINE-CVE-2025-61727 |
| Alpine:v3.24 | go | 1.25.5-r0 | ALPINE-CVE-2025-61727 |
| Debian:12 | golang-1.19 | no fix listed | DEBIAN-CVE-2025-61727 |
| Debian:13 | golang-1.24 | no fix listed | DEBIAN-CVE-2025-61727 |
| Go | stdlib | 1.24.11, 1.25.5 | GO-2025-4175 |
| Ubuntu:22.04:LTS | golang-1.24 | no fix listed | UBUNTU-CVE-2025-61727 |
| Ubuntu:24.04:LTS | golang-1.24 | no fix listed | UBUNTU-CVE-2025-61727 |
| Ubuntu:25.10 | golang-1.24 | no fix listed | UBUNTU-CVE-2025-61727 |
| Ubuntu:26.04:LTS | golang-1.24 | no fix listed | UBUNTU-CVE-2025-61727 |
| Ubuntu:22.04:LTS | golang-1.25 | no fix listed | UBUNTU-CVE-2025-61727 |
| Ubuntu:24.04:LTS | golang-1.25 | no fix listed | UBUNTU-CVE-2025-61727 |
| Ubuntu:25.10 | golang-1.25 | no fix listed | UBUNTU-CVE-2025-61727 |
| Ubuntu:26.04:LTS | golang-1.25 | no fix listed | UBUNTU-CVE-2025-61727 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Go standard library | crypto/x509 | 0 – before 1.24.111.25.0 – before 1.25.5 |