CVE-2026-6667 | PgBouncer missing authorization check in KILL_CLIENT admin command

PgBouncer before 1.25.2 did not perform an appropriate authorization check for the KILL_CLIENT admin command. All users with access to the administration console (which itself requires authorization) could run this command. It would have been correct to allow only users listed in the admin_users parameter.

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-2026-6667 is rated Low Risk (18.1/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.01%). Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.

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-2026-6667

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 2026-05-09 — 0.01% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-6667

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L 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:L)
A normal user session is enough; they don’t have to be admin.
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:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 2.8 1.4 f86ef6dc-4d3a-42ad-8f28-e6d5547a5007

Weakness enumeration for CVE-2026-6667

GitHub Security Advisory for CVE-2026-6667

GHSA-gc77-jrv9-6fjp · Severity: medium — PgBouncer before 1.25.2 did not perform an appropriate authorization check for the KILL_CLIENT...

OS Trackers for CVE-2026-6667

vendor priority summary link
debian not yet assigned CVE-2026-6667 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-2026-6667
ubuntu medium CVE-2026-6667 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-2026-6667

Affected software / configurations for CVE-2026-6667

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

References for CVE-2026-6667

cvelogic Threat Intelligence