What’s Vulnerable › Vulnerabilities
CVE-2025-6203: Vault unauthenticated denial of service through complex json payload
- Severity: high (CVSS 7.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.7% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2025-08-28 · updated 2026-09-26
- Weakness: CWE-770
Description
A malicious user may submit a specially-crafted complex payload that otherwise meets the default request size limit which results in excessive memory and CPU consumption of Vault. This may lead to a timeout in Vault’s auditing subroutine, potentially resulting in the Vault server to become unresponsive. This vulnerability, CVE-2025-6203, is fixed in Vault Community Edition 1.20.3 and Vault Enterprise 1.20.3, 1.19.9, 1.18.14, and 1.16.25.
Affected products
- HashiCorp Vault: from 1.15.0 before 1.16.27; from 1.15.0 before 1.21.0; from 1.18.0 before 1.18.15; from 1.19.0 before 1.19.11; from 1.20.0 before 1.20.5 — fixed in 1.16.27, 1.18.15, 1.19.11, 1.20.5, 1.21.0
How to fix
Upgrade to a fixed version: HashiCorp Vault 1.16.27, 1.18.15, 1.19.11, 1.20.5. Check the vendor advisory for mitigations.
References
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