CVE-2026-81868
Steeltoe: Header-forwarded client cert lacks proof of private-key possession
- State
- Published
- Severity
- 6.5 Medium
- Published
- Sep 17, 2026
- Updated
- Sep 23, 2026
- Reserved
- Aug 27, 2026
Description
Steeltoe is an open source project that provides a collection of libraries that helps users build cloud-native applications. Prior to 4.3.0, Steeltoe.Security.Authorization.Certificate deployments using AddOrgAndSpacePolicies() and UseCertificateAuthorization() trust the public certificate supplied in the X-Client-Cert request header without proving possession of the corresponding private key. Common Cloud Foundry routers do not remove this header from inbound requests. When inbound requests are not restricted to a known trusted proxy source IP, an attacker who obtains the public certificate of an application instance in the target organization or space and can reach the application can spoof X-Client-Cert to bypass the SameOrg and SameSpace policies for the certificate validity period. This issue is fixed in version 4.3.0.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 6.5 Medium | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N | GitHub_M |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
security-advisoriesSteeltoeOSS |
|
References
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