CVE-2026-6664 | PgBouncer integer overflow in PgBouncer network packet parsing

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.

Published: 2026-05-09 Last update: 2026-05-14 Assigner: f86ef6dc-4d3a-42ad-8f28-e6d5547a5007 Source: f86ef6dc-4d3a-42ad-8f28-e6d5547a5007
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-6664 is rated Moderate Risk (47.5/100): CVSS High severity, with low exploitation likelihood (EPSS 0.70%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-6664

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.05% 0.70% +0.65%
2 2026-06-10 0.04% 0.05% +0.01%
3 2026-05-09 — 0.04% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-6664

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 f86ef6dc-4d3a-42ad-8f28-e6d5547a5007

Weakness enumeration for CVE-2026-6664

GitHub Security Advisory for CVE-2026-6664

GHSA-pmgp-q838-fh9g · Severity: high — An integer overflow in network packet parsing code in PgBouncer before 1.25.2 bypasses a boundary...

OS Trackers for CVE-2026-6664

vendor priority summary link
debian not yet assigned CVE-2026-6664 not yet assigned priority: Debian including 1 source packages (pgbouncer), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 3, open 2. https://security-tracker.debian.org/tracker/CVE-2026-6664
ubuntu medium CVE-2026-6664 medium priority: Ubuntu including 1 source packages (pgbouncer), 8 status rows across 8 suites (bionic, focal, jammy, noble, questing, resolute, upstream, xenial): needs-triage 7, released 1. https://ubuntu.com/security/CVE-2026-6664

Affected software / configurations for CVE-2026-6664

Vendor Product Version Raw CPE
pgbouncer pgbouncer < 1.25.2 cpe:2.3:a:pgbouncer:pgbouncer:*:*:*:*:*:*:*:*

References for CVE-2026-6664

cvelogic Threat Intelligence