CVE-2026-6668

Integer overflow in the packet buffer growth logic in PgBouncer through 1.25.2 allows an unauthenticated remote attacker to cause a denial of service. Sufficiently large input makes the buffer size computation overflow, leaving the growth loop unable to terminate. Because PgBouncer serves all clients from a single process, this saturates a CPU core and stalls every pooled connection until the process is killed. Both unauthenticated and authenticated code paths can reach the overflow.

  • Published Sep 23, 2026
  • CVSS 7.5 high
  • 0.4% chance of exploitation in the next 30 days (EPSS)

Affected software

CVE-2026-6668 at the National Vulnerability Database