CVE-2026-22728: 
Wolfi vulnerability analysis and mitigation

CVE-2026-22728 is a scope-widening vulnerability in Bitnami Sealed Secrets for Kubernetes that allows a high-privileged remote attacker to escalate a secret's sealing scope from "strict" or "namespace-wide" to "cluster-wide" via the /v1/rotate endpoint. It affects all versions of github.com/bitnami-labs/sealed-secrets prior to 0.36.0. The vulnerability was published on February 25–26, 2026, with a patch released in version 0.36.0. It carries a CVSS v3.1 base score of 4.9 (Medium) (GitHub Advisory, Bitnami Advisory).

The root cause (CWE-284: Improper Access Control) lies in the rotation handler (controller.go L560–606), which unseals the input SealedSecret to a plain Kubernetes Secret and then reseals it using NewSealedSecret(..., secret). The sealing scope is derived by SecretScope(secret) (sealedsecret_expansion.go L112–122), which reads annotations from the unsealed secret — annotations that were originally sourced from the attacker-controlled spec.template.metadata of the submitted SealedSecret. Because the rotation flow does not validate or preserve the original scope, an attacker can inject the annotation sealedsecrets.bitnami.com/cluster-wide=true into the template metadata before submitting the SealedSecret to the rotate endpoint, causing the rotated output to be cluster-wide regardless of the original strict or namespace-wide constraint. A proof-of-concept (poc.zip) was included in the advisory demonstrating the scope widening (GitHub Advisory, Bitnami Advisory).

Successful exploitation allows an attacker to obtain a rotated SealedSecret that is no longer bound to the victim's original namespace or name, enabling them to unseal it in any namespace under any name and recover the plaintext credentials. This effectively breaks the namespace isolation guarantees of Sealed Secrets, exposing sensitive data — such as API keys, database passwords, and TLS certificates — stored across the entire Kubernetes cluster. The impact is limited to confidentiality (no integrity or availability impact), but the potential for cluster-wide credential exposure makes this significant in multi-tenant or production Kubernetes environments (GitHub Advisory, Bitnami Advisory).

A proof-of-concept exploit (poc.zip) was included in the original security advisory, demonstrating the scope-widening behavior with canonical output confirming scope_widened=true and rotated_scope=cluster-wide. There is no evidence of in-the-wild exploitation at this time, and no threat actor attribution has been reported. The EPSS score is approximately 0.057% (0.038% per Feedly), placing it in the 18th percentile for exploitation likelihood. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. Exploitation requires high privileges (access to submit requests to the /v1/rotate endpoint) and the ability to obtain a victim SealedSecret object (GitHub Advisory, Bitnami Advisory).

1. Reconnaissance: Identify a target Kubernetes cluster running Bitnami Sealed Secrets controller version prior to 0.36.0. Confirm access to the /v1/rotate endpoint (typically requires high-privilege access to the controller service).
2. Obtain a victim SealedSecret: Retrieve a target SealedSecret object via read access to Kubernetes resources (e.g., kubectl get sealedsecret -n <namespace> -o yaml), from logs, or from a GitOps repository where SealedSecrets are stored.
3. Inject malicious annotation: Modify the retrieved SealedSecret YAML to add the annotation sealedsecrets.bitnami.com/cluster-wide: "true" under spec.template.metadata.annotations. Optionally, modify metadata.name and metadata.namespace to retarget the secret.
4. Submit to rotate endpoint: POST the modified SealedSecret to the controller's /v1/rotate endpoint. The rotation handler will unseal the original secret, apply the attacker-controlled template metadata (including the injected annotation), and reseal it with cluster-wide scope.
5. Receive cluster-wide SealedSecret: The rotate response contains a new SealedSecret encrypted with cluster-wide scope, no longer bound to the original namespace or name.
6. Unseal to recover plaintext: Deploy or submit the rotated cluster-wide SealedSecret in any namespace under any name to unseal it and recover the victim's plaintext credentials (GitHub Advisory, Bitnami Advisory).

• Network: Unexpected or anomalous HTTP POST requests to the Sealed Secrets controller's /v1/rotate endpoint, especially from sources that do not normally interact with the controller; requests containing SealedSecret payloads with cluster-wide annotations where the original secret was namespace-scoped.
• Logs: Sealed Secrets controller logs showing rotation requests for secrets that result in a scope change (e.g., output scope differs from input scope); repeated rotation requests for the same SealedSecret from unusual clients.
• Kubernetes Audit Logs: Audit events showing access to SealedSecret resources (get, list, watch) by accounts that do not normally read them, followed by API calls to the controller rotate endpoint.
• Resource Changes: Appearance of new SealedSecret objects in unexpected namespaces with cluster-wide scope annotations that were previously namespace-scoped or strict-scoped; SealedSecrets with modified metadata.name or metadata.namespace fields inconsistent with their original deployment.

Bitnami has released version 0.36.0 of Sealed Secrets, which fixes this vulnerability by ensuring the rotation handler preserves the original sealing scope and does not allow scope widening based on untrusted template metadata. Users should upgrade to version 0.36.0 or later immediately. As interim mitigations: restrict network access to the /v1/rotate endpoint using Kubernetes NetworkPolicies or RBAC to limit which users and services can submit rotation requests; audit existing SealedSecrets for any that have unexpectedly been re-scoped to cluster-wide; and review controller access logs for suspicious rotate endpoint activity prior to patching (GitHub Advisory, Bitnami Advisory).

The vulnerability was reported by security researcher "1seal" and published by maintainer agarcia-oss in the Bitnami Sealed Secrets GitHub repository on February 25, 2026. The advisory was picked up by multiple vulnerability tracking platforms including NVD, ENISA EUVD, GitLab Advisories, and Vulners shortly after disclosure. An openSUSE security announcement was also issued. No significant public social media debate or major media coverage has been identified beyond standard vulnerability database aggregation (Bitnami Advisory, GitHub Advisory).