CVE-2025-59043

CVE-2025-59043 is a high-severity vulnerability in Openbao with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-400.

Key facts

Description

OpenBao is an open source identity-based secrets management system. In OpenBao versions prior to 2.4.1, JSON objects after decoding may use significantly more memory than their serialized version. It is possible to craft a JSON payload to maximize the factor between serialized memory usage and deserialized memory usage, similar to a zip bomb, with factors reaching approximately 35. This can be used to circumvent the max_request_size configuration parameter which is intended to protect against denial of service attacks. The request body is parsed into a map very early in the request handling chain before authentication, which means an unauthenticated attacker can send a specifically crafted JSON object and cause an out-of-memory crash. Additionally, for requests with large numbers of strings, the audit subsystem can consume large quantities of CPU. The vulnerability is fixed in version 2.4.1.

Frequently asked questions

What is CVE-2025-59043?
OpenBao is an open source identity-based secrets management system. In OpenBao versions prior to 2.4.1, JSON objects after decoding may use significantly more memory than their serialized version. It is possible to craft a JSON payload to maximize the factor between serialized memory usage and deserialized memory usage, similar to a zip bomb, with factors reaching approximately 35. This can be used to circumvent the max_request_size configuration parameter which is intended to protect against denial of service attacks. The request body is parsed into a map very early in the request handling chain before authentication, which means an unauthenticated attacker can send a specifically crafted JSON object and cause an out-of-memory crash. Additionally, for requests with large numbers of strings, the audit subsystem can consume large quantities of CPU. The vulnerability is fixed in version 2.4.1.
How severe is CVE-2025-59043?
CVE-2025-59043 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-59043 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-59043?
CVE-2025-59043 affects Openbao. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-59043?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-59043 have an EU (EUVD) identifier?
Yes. CVE-2025-59043 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-34895.
When was CVE-2025-59043 published?
CVE-2025-59043 was published on 2025-10-17 and last updated on 2026-06-17.

References

Affected products (1)

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