{"id":"CVE-2026-59341","aliases":["EUVD-2026-78349","GHSA-qj4p-m373-p2wg"],"status":"published","title":"Sealed Secrets: decryption oracle via Go template injection in unauthenticated controller endpoints","description":"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.\n\n\n\nThe 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.\n\n\n\nMissing 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.\n\n\n\nSide-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 \"...\" }}).\n\n\n\nBy 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.\n\n\n\nAttack vector \u0026 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.","severity":{"version":"3.1","score":4.2,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00403,"percentile":0.34841,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-203"],"published":"2026-09-15T09:16:59Z","modified":"2026-10-28T02:30:39Z","products":[{"vendor":"bitnami","product":"sealed-secrets"}],"references":[{"url":"https://github.com/bitnami/sealed-secrets/security/advisories/GHSA-qj4p-m373-p2wg","tags":["exploit","advisory"]},{"url":"https://github.com/bitnami/sealed-secrets","tags":["package"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59341.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59341","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-59341","title":"Sealed Secrets: decryption oracle via Go template injection in unauthenticated controller endpoints","description":"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.\n\n\n\nThe 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.\n\n\n\nMissing 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.\n\n\n\nSide-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 \"...\" }}).\n\n\n\nBy 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.\n\n\n\nAttack vector \u0026 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.","status":"published","published":"2026-09-15T09:16:59.46Z","modified":"2026-09-16T11:53:25.201Z","cvss":[{"version":"3.1","score":4.2,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-203"],"updated_at":"2026-11-02T14:19:58.560602Z"}],"euvd":[{"id":"EUVD-2026-78349","description":"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.\n\n\n\nThe 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.\n\n\n\nMissing 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.\n\n\n\nSide-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 \"...\" }}).\n\n\n\nBy 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.\n\n\n\nAttack vector \u0026 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.","status":"published","published":"2026-09-15T09:16:59Z","modified":"2026-09-16T11:53:25Z","cvss":[{"version":"3.1","score":4.2,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T17:28:16.201278Z"}],"nvd":[{"id":"CVE-2026-59341","description":"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.\n\n\n\nThe 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.\n\n\n\nMissing 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.\n\n\n\nSide-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 \"...\" }}).\n\n\n\nBy 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.\n\n\n\nAttack vector \u0026 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.","status":"published","published":"2026-09-15T10:17:05.673Z","modified":"2026-09-18T19:21:34.307Z","cvss":[{"version":"3.1","score":4.2,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-203"],"updated_at":"2026-11-02T14:12:47.335523Z"}],"osv":[{"id":"CVE-2026-59341","title":"Sealed Secrets: decryption oracle via Go template injection in unauthenticated controller endpoints","description":"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.\n\n\n\nThe 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.\n\n\n\nMissing 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.\n\n\n\nSide-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 \"...\" }}).\n\n\n\nBy 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.\n\n\n\nAttack vector \u0026 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.","status":"published","published":"2026-09-15T09:16:59.46Z","modified":"2026-10-28T02:30:39.628629241Z","cvss":[{"version":"3.1","score":4.2,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T15:45:12.496548Z"}]}}