Integer overflow in Pgbouncer

CVE-2026-6664

An integer overflow in network packet parsing code in PgBouncer before 1.25.2 bypasses a boundary check and can lead to a crash. An unauthenticated remote attacker can crash PgBouncer with a malformed SCRAM authentication packet.

Vulnerability class: Integer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.007 (52.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 52.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-6664: held from 0.007 to 0.007.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: +0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-6664?
CVE-2026-6664 is a high-severity vulnerability in Pgbouncer, classified under Integer Overflow or Wraparound. CVSS score: 7.5/10. Published 2026-05-09.
How severe is CVE-2026-6664?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2026-6664 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.