Summary
Use of this library in a security-critical context may result in leaking sensitive information, if used to process sensitive fields.
Details
OpenBao (and presumably HashiCorp Vault) have surfaced error messages from mapstructure as follows:
_, _, err := d.getPrimitive(field, schema)
if err != nil {
return fmt.Errorf("error converting input for field %q: %w", field, err)
}
where this calls mapstructure.WeakDecode(...): https://github.com/openbao/openbao/blob/98c3a59c040efca724353ca46ca79bd5cdbab920/sdk/framework/field_data.go#L181-L193
func (d *FieldData) getPrimitive(k string, schema *FieldSchema) (interface{}, bool, error) {
raw, ok := d.Raw[k]
if !ok {
return nil, false, nil
}
switch t := schema.Type; t {
case TypeBool:
var result bool
if err := mapstructure.WeakDecode(raw, &result); err != nil {
return nil, false, err
}
return result, true, nil
Notably, WeakDecode(...) eventually calls one of the decode helpers, which surfaces the original value via strconv helpers:
& more. These are different code paths than are fixed in the previous iteration at https://github.com/go-viper/mapstructure/security/advisories/GHSA-fv92-fjc5-jj9h.
PoC
To reproduce with OpenBao:
$ podman run --pull=always -p 8300:8300 openbao/openbao:latest server -dev -dev-root-token-id=root -dev-listen-address=0.0.0.0:8300
and in a new tab:
$ BAO_TOKEN=root BAO_ADDR=http://localhost:8300 bao auth enable userpass
Success! Enabled userpass auth method at: userpass/
$ curl -X PUT -H "X-Vault-Request: true" -H "X-Vault-Token: root" -d '{"ttl":"asdf"}' "http://localhost:8200/v1/auth/userpass/users/asdf"
--> server logs:
2025-06-25T21:32:25.101-0500 [ERROR] core: failed to run existence check: error="error converting input for field \"ttl\": time: invalid duration \"asdf\""
Impact
This is an information disclosure bug with little mitigation. See https://discuss.hashicorp.com/t/hcsec-2025-09-vault-may-expose-sensitive-information-in-error-logs-when-processing-malformed-data-with-the-kv-v2-plugin/74717 for a previous version. That version was fixed, but this is in the second part of that error message (starting at '' expected a map, got 'string' -- when the field type is string and a map is provided, we see the above information leak -- the previous example had a map type field with a string value provided).
This was rated 4.5 Medium by HashiCorp in the past iteration.
CVE-2025-11065 has a CVSS score of 5.3 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.4.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2025-11065? CVE-2025-11065 is a medium-severity security vulnerability in github.com/go-viper/mapstructure/v2 (go), affecting versions <= 2.3.0. It is fixed in 2.4.0.
- How severe is CVE-2025-11065? CVE-2025-11065 has a CVSS score of 5.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of github.com/go-viper/mapstructure/v2 are affected by CVE-2025-11065? github.com/go-viper/mapstructure/v2 (go) versions <= 2.3.0 is affected.
- Is there a fix for CVE-2025-11065? Yes. CVE-2025-11065 is fixed in 2.4.0. Upgrade to this version or later.
- Is CVE-2025-11065 exploitable, and should I be worried? Whether CVE-2025-11065 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-11065 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2025-11065? Upgrade
github.com/go-viper/mapstructure/v2to 2.4.0 or later.