CVE-2026-119276: MariaDB Connector/J: Rogue server can drive large heap allocations from server-declared lengths in OK packets

Severity: medium (CVSS 5.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-29 · updated 2026-10-30
Weakness: CWE-130

Description

MariaDB Connector/J is used to connect applications developed in Java to MariaDB and MySQL databases. From 3.0.0 until 3.3.7, 3.4.5, and 3.5.11, when CLIENT_SESSION_TRACK was negotiated, the OkPacket.parse() and OkPacket.parseWithInfo() paths allocated byte arrays using server-declared lengths for the OK packet info field and session-state variable names and values before confirming that the bytes remained in the packet. A malicious or compromised server, or a machine-in-the-middle attacker, could send a small OK packet declaring a much larger length and repeatedly force attacker-controlled heap allocations before the subsequent copy failed. This could create garbage-collection pressure or an OutOfMemoryError in the client application. This issue is fixed in versions 3.3.7, 3.4.5, and 3.5.11.

Affected products

mariadb-corporation mariadb-connector-j: from 3.0.0, < 3.3.7; from 3.4.0, < 3.4.5; from 3.5.0, < 3.5.11

References

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