CVE-2025-6203: vault DoS — Fix

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.

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CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-770 CWE-770

Affected Products

Vendor	Product	Versions
hashicorp	vault	1.15.0 — 1.16.27
hashicorp	vault	1.15.0 — 1.21.0
hashicorp	vault	1.18.0 — 1.18.15
hashicorp	vault	1.19.0 — 1.19.11
hashicorp	vault	1.20.0 — 1.20.5

References

Advisories & Patches

https://discuss.hashicorp.com/t/hcsec-2025-24-vault-denial-of-service-though-complex-json-payloads/76393

Frequently Asked Questions

What is CVE-2025-6203? +

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. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2025-6203? +

CVE-2025-6203 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-6203? +

CVE-2025-6203 affects products from hashicorp, specifically: vault. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-6203? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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