CVE-2026-34308

MEDIUM

MySQL Server 8.0.0-8.0.45, 8.4.0-8.4.8, 9.0.0-9.6.0 - Denial of Service in JSON Component

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2026-34308. PoCs published by JoakimBulow.

AI-analyzed exploit summary This repository contains a functional proof-of-concept exploit for CVE-2026-34308, a denial-of-service vulnerability in MySQL Server's JSON component. The exploit leverages a deep linear chain of JSON Schema $ref pointers to trigger stack exhaustion, causing the server to crash.

Description

Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: JSON). Supported versions that are affected are 8.0.0-8.0.45, 8.4.0-8.4.8 and 9.0.0-9.6.0. Easily exploitable vulnerability allows low privileged attacker with network access via multiple protocols to compromise MySQL Server. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server. CVSS 3.1 Base Score 6.5 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).

Exploits (1)

nomisec WORKING POC
by JoakimBulow · poc
https://github.com/JoakimBulow/CVE-2026-34308

This repository contains a functional proof-of-concept exploit for CVE-2026-34308, a denial-of-service vulnerability in MySQL Server's JSON component. The exploit leverages a deep linear chain of JSON Schema $ref pointers to trigger stack exhaustion, causing the server to crash.

Classification
Working Poc 100%
Attack Type
Dos
Complexity
Trivial
Reliability
Reliable
Target: MySQL Server (versions 8.0.0–8.0.45, 8.4.0–8.4.8, 9.0.0–9.6.0)
Auth required
Prerequisites: Authenticated MySQL user with minimal privileges (USAGE on *.* is sufficient)
devstral-2 · analyzed Apr 30, 2026 Full analysis →

References (1)

Core 1
Core References
Vendor Advisory vendor-advisory
Oracle Advisory
https://www.oracle.com/security-alerts/cpuapr2026.html

Scores

CVSS v3 6.5
EPSS 0.0030
EPSS Percentile 21.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-400
Status published
Products (4)
oracle/mysql_server 8.0.0 - 8.0.45
Oracle Corporation/MySQL Server 8.0.0 - 8.0.45
Oracle Corporation/MySQL Server 8.4.0 - 8.4.8
Oracle Corporation/MySQL Server 9.0.0 - 9.6.0
Published Apr 21, 2026
Tracked Since Apr 22, 2026