CVE-2025-6203 | Vault unauthenticated denial of service through complex json payload

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.

Published: 2025-08-28 Last update: 2025-12-18 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-6203 is rated Low Risk (38.2/100): CVSS High severity, with low exploitation likelihood (EPSS 0.08%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-6203

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-14 0.05% 0.08% +0.03%
2 2026-05-13 0.06% 0.05% -0.01%
3 2026-03-24 — 0.06% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-6203

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2025-6203

GitHub Security Advisory for CVE-2025-6203

GHSA-8f82-53h8-2p34 · Severity: high · Ecosystem: go — HashiCorp Vault Community Edition Denial of Service Though Complex JSON Payloads

OS Trackers for CVE-2025-6203

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2025-6203

Affected software / configurations for CVE-2025-6203

Vendor Product Version Raw CPE
hashicorp vault >= 1.15.0, < 1.16.27 cpe:2.3:a:hashicorp:vault:*:*:*:*:enterprise:*:*:*
hashicorp vault >= 1.15.0, < 1.21.0 cpe:2.3:a:hashicorp:vault:*:*:*:*:-:*:*:*
hashicorp vault >= 1.18.0, < 1.18.15 cpe:2.3:a:hashicorp:vault:*:*:*:*:enterprise:*:*:*
hashicorp vault >= 1.19.0, < 1.19.11 cpe:2.3:a:hashicorp:vault:*:*:*:*:enterprise:*:*:*
hashicorp vault >= 1.20.0, < 1.20.5 cpe:2.3:a:hashicorp:vault:*:*:*:*:enterprise:*:*:*

References for CVE-2025-6203

cvelogic Threat Intelligence