CVE-2026-48772
CriticalCVSS 10.0Exploitation Probability (EPSS)
Low risk8th percentile — higher than 8% of all known CVEs
Summary
ProxySQL in versions 2.0.0 through 3.0.8 incorrectly accepts a malformed PROXY protocol header, allowing attackers to spoof source addresses. This leads to a bypass of routing and access control rules, enabling attackers to manipulate queries as if they were trusted users.
Risk Assessment
Organizations may be exposed to unauthorized data access and query manipulation, potentially leading to serious security breaches. An attacker with access to the frontend port can exploit this vulnerability to take control over query routing.
Recommendation
It is recommended to upgrade ProxySQL to version 3.0.9 or later to mitigate this vulnerability. Additionally, consider restricting access to the frontend port to trusted sources only.
Original NVD description (English source)
ProxySQL is a proxy for MySQL and its forks, as well as PostgreSQL. In versions 2.0.0 through 3.0.8, the ProxySQL MySQL frontend accepts the `PROXY UNKNOWN <addr> <addr> <port> <port>\r\n` PP1 frame as a well-formed PROXY protocol header. The HAProxy PROXY protocol v1 specification says that when the protocol token is `UNKNOWN`, the receiver MUST ignore any address fields that follow it, because the proxy has declared it cannot determine the client identity. ProxySQL parses those address fields anyway via `sscanf` and writes the spoofed source address into the session's `addr.addr` field. From there it flows directly into the query-rule matcher, where the `client_addr` predicate decides routing and ACL. When `mysql-proxy_protocol_networks = '*'` (the default), any TCP peer can send a PP1 frame and choose any source IP claim. With that, any `mysql_query_rules` row pinned to a `client_addr` value is forgeable: the attacker writes the address they want to match into the PP1 line, and ProxySQL routes their query as if it came from that address. In practice this is a routing and ACL bypass. Real deployments use `client_addr` for read-write splitting (internal apps go to the primary, public traffic to read replicas), per-app schema pinning, and query-filter rules (DDL allowed only from admin CIDR, public queries blocked from dangerous patterns). An attacker that can reach the frontend port can forge their way into any of those routes. Version 3.0.9 patches this issue.