---
id: CVE-2026-59341
title: >-
  A security vulnerability exists in the Sealed Secrets controller's
  unauthenticated POST endpoints
summary: >-
  A security vulnerability exists in the Sealed Secrets controller's
  unauthenticated POST endpoints. By submitting a modified payload containing
  custom Go template logic in spec.template.data, an attacker with internal
  network access can a…
severity: medium
cvss: 4.2
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:N'
cwe:
  - CWE-203
vendor: Bitnami
product: sealed-secrets
affected:
  - sealed-secrets <= 0.38.4
published: '2026-09-15'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T19:21:34.307'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-59341'
references:
  - url: 'https://github.com/bitnami/sealed-secrets'
    label: security@vmware.com
  - url: >-
      https://github.com/bitnami/sealed-secrets/security/advisories/GHSA-qj4p-m373-p2wg
    label: security@vmware.com
  - url: >-
      https://github.com/bitnami/sealed-secrets/security/advisories/GHSA-qj4p-m373-p2wg
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
epss: 0.00313
epssPercentile: 0.24447
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-15T17:27:25.731287Z'
ingestedAt: '2026-09-15T09:34:49.387Z'
---

## Overview

A security vulnerability exists in the Sealed Secrets controller's unauthenticated POST endpoints. By submitting a modified payload containing custom Go template logic in spec.template.data, an attacker with internal network access can abuse the handler as a decryption oracle to recover the full plaintext of any sealed secret.



The POST /v1/verify and /v1/rotate handlers call Unseal() to decrypt target secrets, then render any Go templates found in spec.template.data.* using the decrypted payload as the evaluation context (pkg/apis/sealedsecrets/v1alpha1/sealedsecret_expansion.go). Errors encountered during template execution are directly reflected in the resulting HTTP response status codes.



Missing AEAD label binding: the spec.template.data field is omitted from the AEAD authenticated-data label binding ciphertext to metadata. As a result, an attacker can copy a target's valid metadata and encryptedData verbatim, satisfying AEAD decryption and label validation, while freely replacing spec.template.data with arbitrary template logic.



Side-channel oracle: template execution errors map directly to HTTP response codes. HTTP 200 (OK) indicates template execution succeeded; HTTP 409 (Conflict) indicates template execution failed (e.g. via {{ fail "..." }}).



By injecting conditional statements such as {{ if eq (substr 0 1 .password) "S" }}ok{{ else }}{{ fail "x" }}{{ end }}, an attacker receives an HTTP 200 status when a character guess is correct and an HTTP 409 when it is incorrect. This differential response leaks one character-equality bit per request, allowing full secret extraction over successive queries.



Attack vector & prerequisites: unauthenticated; requires network access to the controller's internal service port (:8080). Although this service is not exposed to the public internet by default, it is accessible to any pod within the Kubernetes cluster or via a kubectl port-forward connection.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.