CVE-2026-102664

High CVSS 7.1

Published 2026-11-04 · last changed 2026-11-04

The fix

We hold no Microsoft remediation data for CVE-2026-102664, which normally means it is not a Windows CVE. For non-Microsoft software the fix is the vendor's own updated release, and the affected versions are listed below.

What it is

ProxySQL is a proxy for MySQL and its forks, as well as PostgreSQL. Prior to 3.0.10, 3.1.10, and 4.0.10, decompress_mysql_payload() in lib/mysql_data_stream.cpp accepts a zlib stream when uncompress() returns Z_OK without checking that the actual output length equals the attacker-controlled payload_length. An authenticated MySQL client that negotiates compression can overstate payload_length, causing buffer2array() to parse the uninitialized tail of a heap buffer as MySQL packet headers and forward stale data to the backend. Backend error responses can disclose prior SQL queries, result data, credentials, or session state, and malformed lengths can also cause excessive allocations. This issue is fixed in versions 3.0.10, 3.1.10, and 4.0.10.

Sources

NVD record for CVE-2026-102664

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