{"id":"CVE-2025-59043","aliases":["GHSA-g46h-2rq9-gw5m","BIT-openbao-2025-59043","GO-2025-4039"],"title":"OpenBao has potential Denial of Service vulnerability when processing malicious unauthenticated JSON requests","summary":"OpenBao has potential Denial of Service vulnerability when processing malicious unauthenticated JSON requests","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","vendor":"openbao","product":"github.com/openbao/openbao","ecosystem":"go","affected":["github.com/openbao/openbao < 2.4.1"],"patched":["github.com/openbao/openbao 2.4.1"],"published":"2025-10-17","updated":"2026-07-27","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/GHSA-g46h-2rq9-gw5m","references":[{"url":"https://github.com/openbao/openbao/security/advisories/GHSA-g46h-2rq9-gw5m"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-59043"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-6203"},{"url":"https://github.com/openbao/openbao/pull/1756"},{"url":"https://github.com/openbao/openbao/commit/d418f238bc99adc72c73109faf574cc2b672880c"},{"url":"https://discuss.hashicorp.com/t/hcsec-2025-24-vault-denial-of-service-though-complex-json-payloads/76393"},{"url":"https://github.com/openbao/openbao"},{"url":"https://github.com/openbao/openbao/blob/788536bd3e10818a7b4fb00aac6affc23388e5a9/http/logical.go#L50"}],"tags":["osv","go"],"epss":0.00688,"epssPercentile":0.51292,"ingestedAt":"2026-07-27T19:08:54.724Z","slug":"CVE-2025-59043","body":"## Overview\n\n### 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.\n\n## Affected packages\n\n- `github.com/openbao/openbao < 2.4.1`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `github.com/openbao/openbao 2.4.1`","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}