CVE-2026-119279: MariaDB Connector/J: Length-encoded integers larger than Integer.MAX_VALUE were truncated before being used as lengths

Vulnerability summary

CVE-2026-119279 is a medium (CVSS 5.9) vulnerability in mariadb-corporation mariadb-connector-j. EPSS estimates a 0.35% chance of exploitation in the next 30 days, higher than 28.7% of scored vulnerabilities.

Timeline

1. 29-10-2026
   PublishedVulnerability first disclosed.
2. 03-11-2026
   Last modifiedVulnerability information updated.

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 3.5.10, the ReadableByteBuf.readLength() and ReadableByteBuf.readIntLengthEncodedNotNull() methods narrowed the protocol's unsigned 8-byte length-encoded integer to a Java int without checking that the value fit a non-negative integer. Values above Integer.MAX_VALUE could wrap to a negative or unrelated length that downstream allocation and read paths used. A malicious or compromised server, or a machine-in-the-middle attacker, could trigger NegativeArraySizeException, out-of-bounds failures, or oversized allocation behavior in client connection handling. This issue is fixed in versions 3.3.7, 3.4.5, and 3.5.10.

• CWE-130Improper Handling of Length Parameter InconsistencyThe product parses a formatted message or structure, but it does not handle or incorrectly handles a length field that is inconsistent with the actual length of the associated data.
• CWE-190Integer Overflow or WraparoundThe product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.