Authentication Bypass in Cloud Foundry UAA (CVE-2026-59358)
Summary
Authentication bypass in Cloud Foundry UAA (CVE-2026-59358). Risk of unauthorized operations or information disclosure. Exploitable via POST /oauth/clients.
Original description
The description as published by the source.
Improper authentication (CWE-287) in the OAuth token endpoint in Cloud Foundry UAA allows a remote, authenticated attacker holding a valid user access token to obtain a fully-privileged client_credentials token for the OAuth client that issued it, by presenting the user token as an OAuth 2.0 Bearer credential on a client_credentials grant request in place of the client’s configured secret.
UAA’s client_credentials handling does not verify that the Bearer credential supplied for client authentication is actually a client credential (a client secret or a valid configured client authentication method); it accepts any valid access token whose client_id matches the request. A token obtained by a normal end user through a public authorization_code + PKCE flow — scoped only to uaa.user, carrying a user_id, and recording client_auth_method=none — satisfies this check. That user token cannot itself administer OAuth clients (POST /oauth/clients correctly returns 403), but when replayed as Bearer authentication on a client_credentials request for the same client, UAA issues a new client-only token carrying the client’s full authorities, such as clients.write. An attacker can use that token to create arbitrary new OAuth clients, including clients with attacker-chosen authorities, without ever possessing the client’s actual secret.
Exploitation requires a valid user access token (the attacker’s own) for a client that is configured to support both a public, user-facing authorization flow…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-59358 has been found in Cloud Foundry UAA.
Attackers can target a specific entry point like POST /oauth/clients over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Cloud Foundry UAA CVE-2026-59358" on the vendor's site.
CVE-2026-59358 (Cloud Foundry UAA) — CWE-287
Attack surface: POST /oauth/clients
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Authentication bypass (CWE-287) exists in Cloud Foundry UAA. Attackers reach the vulnerable code path via POST /oauth/clients.
Check the vendor advisory for the affected versions of Cloud Foundry UAA. Attack surface: POST /oauth/clients.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual POST /oauth/clients requests with malformed payloads or SQL meta-characters. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Cloud Foundry UAA を使っているサービスとバージョンを洗い出す。
-
2Hunt for indicators of compromise detect
grep 'POST /oauth/clients' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /oauth/clientsへの異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。 -
3Post-deployment verification verify
Replay attack against POST /oauth/clients on staging to confirm patch closes the vectorパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 2 と同じログクエリでアラート再発が無いか継続監視。
References
- web security@vmware.com
- web nvd.nist.gov
- web cloudfoundry.org
- web github.com