Cross-namespace data access via unrestricted CEL requests
Published Mar 30, 2026 · Updated Mar 30, 2026
SSRF in Kyverno's CEL HTTP library allows remote authenticated users to read internal service data through namespaced policies. The http.Get and http.Post implementations in pkg/cel/libs/http/http.go issue requests to supplied URLs without destination validation or namespace scoping. Namespace-scoped policy creation permission is sufficient to make the admission controller reach cross-namespace services or metadata endpoints and return response data in policy errors.
Summary
What happened
SSRF in Kyverno's CEL HTTP library allows remote authenticated users to read internal service data through namespaced policies. The http.Get and http.Post implementations in pkg/cel/libs/http/http.go issue requests to supplied URLs without destination validation or namespace scoping. Namespace-scoped policy creation permission is sufficient to make the admission controller reach cross-namespace services or metadata endpoints and return response data in policy errors.
The record
- CVE
- CVE-2026-4789
- Published
- Mar 30, 2026
- Updated
- Mar 30, 2026
- Vendor
- Kyverno
- Product
- Kyverno
- Classifications
- CWE-918, T1552.005
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 30, 2026CVE publishedPublication date reported by the CVE source.
- Mar 30, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1.16.0
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Kyverno CEL SSRF proof-of-concept scriptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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