{"id":"CVE-2026-59341","state":"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 & 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.","publishedAt":"2026-09-15T09:16:59.460Z","updatedAt":"2026-09-16T11:53:25.201Z","severity":{"score":4.2,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:N","source":"vmware"},"assigner":"vmware","products":["Bitnami sealed-secrets"],"affected":[{"vendor":"Bitnami","product":"sealed-secrets","versions":[{"version":"0","status":"affected","lessThanOrEqual":"0.38.4","versionType":"semver"},{"version":"0.40.0","status":"unaffected","versionType":"semver"}],"repo":"https://github.com/bitnami/sealed-secrets"}],"references":["https://github.com/bitnami/sealed-secrets/security/advisories/GHSA-qj4p-m373-p2wg","https://github.com/bitnami/sealed-secrets"],"weaknesses":["CWE-203"],"ingestedAt":"2026-10-29T20:12:32.778Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/59xxx/CVE-2026-59341.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-59341","state":"PUBLISHED","datePublished":"2026-09-15T09:16:59.460Z","dateUpdated":"2026-09-16T11:53:25.201Z","assignerShortName":"vmware","assignerOrgId":"dcf2e128-44bd-42ed-91e8-88f912c1401d","dateReserved":"2026-07-04T18:14:34.672Z"},"containers":{"cna":{"title":"Sealed Secrets: decryption oracle via Go template injection in unauthenticated controller endpoints","descriptions":[{"lang":"en","value":"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 & 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."}],"affected":[{"vendor":"Bitnami","product":"sealed-secrets","versions":[{"version":"0","status":"affected","lessThanOrEqual":"0.38.4","versionType":"semver"},{"version":"0.40.0","status":"unaffected","versionType":"semver"}],"repo":"https://github.com/bitnami/sealed-secrets"}],"references":[{"url":"https://github.com/bitnami/sealed-secrets/security/advisories/GHSA-qj4p-m373-p2wg"},{"url":"https://github.com/bitnami/sealed-secrets"}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"version":"3.1","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"HIGH","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"NONE","availabilityImpact":"NONE","baseSeverity":"MEDIUM","baseScore":4.2,"vectorString":"CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:N"}}],"providerMetadata":{"shortName":"vmware","orgId":"dcf2e128-44bd-42ed-91e8-88f912c1401d","dateUpdated":"2026-09-15T09:16:59.460Z"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/bitnami/sealed-secrets/security/advisories/GHSA-qj4p-m373-p2wg","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-15T17:27:25.731287Z","id":"CVE-2026-59341","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-203","type":"CWE","lang":"en","description":"CWE-203 Observable Discrepancy"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-16T11:53:25.201Z"}}]}}}