CVE-2021-43801 - CVE House
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Status published High CVE-2021-43801

Uncaught Exception in mercurius

Vulnerability Description

Mercurius is a GraphQL adapter for Fastify. Any users from Mercurius@8.10.0 to 8.11.1 are subjected to a denial of service attack by sending a malformed JSON to `/graphql` unless they are using a custom error handler. The vulnerability has been fixed in https://github.com/mercurius-js/mercurius/pull/678 and shipped as v8.11.2. As a workaround users may use a custom error handler.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

References

More from mercurius-js

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CVE-2025-64166
Mercurius: Incorrect Content-Type parsing can lead to CSRF attack
Medium 5.4
CVE-2023-22477
Mercurius is vulnerable to denial of service (DoS) when using subscriptions
Medium 5.3

Affected Vendor

mercurius-js

View all reports →

Affected Software

mercurius
Vulnerable Versions:
>= 8.10.0, < 8.11.2

Timeline

Official Publish: December 13th, 2021
Last Modified: August 4th, 2024
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weaknesses (CWE)

CWE-754

MITRE ATT&CK TTPs

T1190 Exploit Public-Facing Application
Initial Access
T1068 Exploitation for Privilege Escalation
Privilege Escalation
T1499 Endpoint Denial of Service
Impact
T1562 Impair Defenses
Defense Evasion
T1005 Data from Local System
Collection