{"id":"CVE-2025-59043","aliases":["BIT-openbao-2025-59043","GHSA-g46h-2rq9-gw5m","GO-2025-4039"],"url":"https://o3.security/vulnerability/CVE-2025-59043","summary":"OpenBao vulnerable to denial of service via malicious JSON request processing","details":"### Summary\n\nJSON objects after decoding might use more memory than their serialized version. It is possible to tune a JSON to maximize the factor between serialized memory usage and deserialized memory usage (similar to a zip bomb). While reproducing the issue, we could reach a factor of about 35. This can be used to circumvent the [`max_request_size` (https://openbao.org/docs/configuration/listener/tcp/) configuration parameter, which is meant to protect against Denial of Service attacks, and also makes Denial of Service attacks easier in general, as the attacker needs much less resources.\n\n### Details\n\nThe request body is parsed into a `map[string]interface{}` https://github.com/openbao/openbao/blob/788536bd3e10818a7b4fb00aac6affc23388e5a9/http/logical.go#L50 very early in the request handling chain (before authentication), which means an attacker can send a specifically crafted JSON object and cause an OOM crash. Additionally, for simpler requests with large numbers of strings, the audit subsystem can consume large quantities of CPU. \n\nTo remediate, set `max_request_json_memory` and `max_request_json_strings`.\n\n### Impact\n\n- Unauthenticated Denial of Service\n\n### Resources\n\nThis issue was disclosed directly to HashiCorp and is the OpenBao equivalent of the following tickets:\n\n- https://discuss.hashicorp.com/t/hcsec-2025-24-vault-denial-of-service-though-complex-json-payloads/76393\n- https://nvd.nist.gov/vuln/detail/CVE-2025-6203\n\nHashiCorp attributes the problem to the audit subsystem. For OpenBao, it was noted the problem was additionally in the requests handling logic.","published":"2025-10-17T16:03:23.584Z","modified":"2026-08-12T03:51:45.847347853Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.00647,"percentile":0.48233,"asOf":"2026-08-24"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/openbao/openbao","fixedVersion":"2.4.1"}],"fix":{"url":"https://github.com/openbao/openbao/commit/d418f238bc99adc72c73109faf574cc2b672880c","label":"openbao/openbao@d418f23"},"references":[{"type":"WEB","url":"https://github.com/openbao/openbao/blob/788536bd3e10818a7b4fb00aac6affc23388e5a9/http/logical.go#L50"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/59xxx/CVE-2025-59043.json"},{"type":"ADVISORY","url":"https://github.com/openbao/openbao/security/advisories/GHSA-g46h-2rq9-gw5m"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-59043"},{"type":"FIX","url":"https://github.com/openbao/openbao/commit/d418f238bc99adc72c73109faf574cc2b672880c"},{"type":"FIX","url":"https://github.com/openbao/openbao/pull/1756"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-6203"},{"type":"WEB","url":"https://discuss.hashicorp.com/t/hcsec-2025-24-vault-denial-of-service-though-complex-json-payloads/76393"},{"type":"PACKAGE","url":"https://github.com/openbao/openbao"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:45.847347853Z"}}