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Fencer Vulns
high 7.5

CVE-2026-6668 json

Integer overflow causes an infinite loop in packet buffer growth in PgBouncer

published 2026-09-23 46 d ago modified 2026-10-01 39 d ago also BIT-pgbouncer-2026-6668 , EUVD-2026-85363

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 47%
public exploits
0
none known

Summary

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.

Patch / fix

  • bitnami pgbouncer 1.26.0
  • pgbouncer pgbouncer 1.26.0
  • pgbouncer Debian 14 1.26.0-1

debian advisories DEBIAN-CVE-2026-6668

  • pgbouncer hummingbird 1 1.26.0-0.1.hum1

red hat advisories RHSA-2026:70698

  • pgbouncer Azure Linux 3.0 1.26.0-1

azure linux advisories AZL-103433

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-6668 updated cvss 7.5

pgbouncer: PgBouncer: Denial of Service via integer overflow in packet buffer growth

  • Red Hat Hardened Images pgbouncer 1.26.0-0.1.hum1
    fixed: vendor fix RHSA-2026:70698

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
46 d ago

Exploit prediction

0.57% chance of exploitation in the next 30 days, higher than 47% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
bitnami pgbouncer
<1.26.0
1.26.0

Affected products

  • n/a PgBouncer

Classification

Weakness
  • CWE-190 Integer Overflow or Wraparound
  • CWE-835 Loop with Unreachable Exit Condition

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.