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Vulnerability · Published Nov 4, 2026 · Assigned by GitHub_M

CVE-2026-102664ProxySQL: Uninitialized heap read in MySQL compressed packet decompression via zlib path

High 7.1

In plain English

A high-severity security flaw in proxysql from sysown. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 23% of all known vulnerabilities).

Severity (CVSS 3.1)7.1High
Exploit odds (30 days)0.3%top 77.1% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

VendorProductVersions
sysown proxysql < 3.0.10>= 3.1.0, < 3.1.10>= 4.0.0, < 4.0.10

Weakness: CWE-908 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L

References