CVE-2026-54745: Kubeflow Pipelines: Unauthenticated SSRF and HTTP smuggling in Kubeflow Pipelines frontend /_proxy/ route, bypasses ENABLE_AUTHZ=true
Kubeflow Pipelines enables users to build and deploy portable, scalable machine learning workflows. Prior to 2.17.0, the Kubeflow Pipelines frontend exposes an unauthenticated server-side request forgery vulnerability through the /_proxy/ route in frontend/server/proxy-middleware.ts. The _routePathWithReferer() function accepts an arbitrary attacker-controlled HTTP or HTTPS target and passes its origin to createProxyMiddleware without a host allowlist or filtering for loopback, link-local, RFC1918, or cluster-local addresses. The route remains outside the authorization middleware when ENABLE_AUTHZ=true and is reachable through /apis/v1beta1/_proxy/, /apis/v2beta1/_proxy/, /pipeline/apis/v1beta1/_proxy/, and /pipeline/apis/v2beta1/_proxy/, including through a crafted Referer header. Requests can forward attacker-controlled methods, headers such as Authorization, Cookie, and X-Forwarded-For, and POST bodies to reachable internal services, while returning the upstream response to the unauthenticated client. This can expose cloud metadata credentials, Kubernetes or service APIs, and other cluster-internal endpoints to unauthorized read or modification. This issue is fixed in version 2.17.0.
Security readout for executives and security teams
Plain-English summary
Kubeflow Pipelines before 2.17.0 may let an unauthenticated internet or network user make the frontend contact sensitive internal services and return their responses. This could expose cloud credentials or enable unauthorized changes to Kubernetes and service APIs. Enabling authorization does not protect the affected proxy route.
Executive priority
Treat this as an emergency upgrade for reachable Kubeflow Pipelines deployments. The vulnerability crosses an authorization boundary and may turn frontend access into access to sensitive internal systems. Prioritize asset identification, upgrading to 2.17.0, log review, and credential rotation where evidence suggests internal credential exposure.
Technical view
The frontend /_proxy/ route accepts attacker-controlled HTTP or HTTPS destinations without filtering loopback, link-local, private, or cluster-local addresses. It remains outside authorization middleware when ENABLE_AUTHZ=true and can forward methods, sensitive headers, and request bodies. The supplied sources describe SSRF and HTTP smuggling risk. Version 2.17.0 contains the fix.
Likely exposure
Deployments running Kubeflow Pipelines versions earlier than 2.17.0 are affected when an attacker can reach the frontend proxy routes. Exposure is especially consequential where the frontend can access cloud metadata, Kubernetes APIs, or privileged internal services. The bundle does not establish how many deployments expose these routes publicly.
Exploitation context
The CVSS 3.1 score is 10.0, reflecting remote, unauthenticated exploitation with low complexity and potentially severe confidentiality, integrity, and availability impact. The CVE is not identified as KEV, and the supplied sources provide no evidence of active exploitation. Absence from KEV does not establish that exploitation is impossible.
Researcher notes
Affected paths include /apis/v1beta1/_proxy/, /apis/v2beta1/_proxy/, and their /pipeline-prefixed equivalents, including crafted Referer handling. The vulnerable routing passes an attacker-selected origin to proxy middleware and can relay upstream responses. Validate exposure through configuration, version, routing, and logs; avoid intrusive testing against production internal services.
Mitigation direction
Upgrade Kubeflow Pipelines to version 2.17.0 or later.
Prioritize deployments whose frontend is reachable from untrusted networks.
Review vendor guidance before applying any compensating control not documented in the supplied sources.
Rotate exposed credentials if investigation indicates access to metadata or internal authentication services.
Validation and detection
Inventory deployed Kubeflow Pipelines versions and confirm none are earlier than 2.17.0.
Map network paths from the frontend to metadata, Kubernetes, and internal service endpoints.
Review frontend access logs for unexpected requests involving the affected _proxy routes.
Check cloud, Kubernetes, and service audit logs for correlated unauthorized access or changes.
Confirm authorization settings were not treated as sufficient protection for these routes.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Potential ATT&CK relevance
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
cwe · medium confidence lookup
CWE-284: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
CWE-918: Information exposure and cloud metadata lookup
Information exposure and SSRF weaknesses can make discovery, cloud metadata, and credential material review relevant. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
The CVE wording references SSRF or metadata access, so cloud discovery and credential material review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
The affected technology mentions containers, so container-specific ATT&CK technique review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
1CVSS vectors
3Timeline events
1ADP providers
5Source links
SSVC decision data
CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: pocAutomatable: yesTechnical Impact: total
CVSS vector scores
1 official score
We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
CWE-284 · source CWE mapping
Improper Access Control
Improper Access Control represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Server-Side Request Forgery (SSRF) represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.