CVE-2026-92870
Description
A flaw was found in Pgpool-II. Due to a stack-based buffer overflow, an unauthenticated remote attacker can trigger abnormal process termination by sending specially crafted input to the server. This issue leads to a Denial of Service (DoS), making the service unavailable to legitimate users.
Statement
This vulnerability is rated as having an Important severity because it enables remote, unauthenticated attackers to abruptly terminate the service without prior credentials, elevating the risk beyond Moderate due to the immediate outage imposed on all dependent database operations. Pgpool-II acts as a connection pooler and proxy for PostgreSQL environments; crashing the daemon severs active connections and halts transactional processing. This component is not distributed in Red Hat Enterprise Linux and is only packaged through community channels such as Fedora.
Mitigation
Restrict network reachability to the Pgpool-II listening port (by default TCP port 9999) using firewalld so that only trusted client application hosts can initiate connections.
To limit access to a trusted source subnet using firewalld rich rules, run:
firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="192.0.2.0/24" port port="9999" protocol="tcp" accept'
firewall-cmd --reload
If the Pgpool-II service is not required on the system, stop and disable it:
systemctl stop pgpool
systemctl disable pgpool
Caveats: Restricting incoming traffic blocks untrusted network hosts from reaching the proxy. Stopping the daemon prevents client connections from being pooled or routed to PostgreSQL backend servers. Warning: Reloading firewall rules or stopping the service will disrupt active client connections and cause transient connectivity outages.
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Write operations could cause memory corruption. In some cases, an adversary can modify control data such as return addresses in order to execute unexpected code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
Attempting to access out-of-range, invalid, or unauthorized memory could cause the product to crash.
Other
Technical Impact: Unexpected State
Subsequent write operations can produce undefined or unexpected results.
Frequently Asked Questions
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