# CVE-2026-6668: Integer overflow causes an infinite loop in packet buffer growth in PgBouncer

CVE-2026-6668 is fixed in pgbouncer on 1 platform by DEBIAN-CVE-2026-6668 (version 1.26.0-1), released October 4, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-6668
- Priority: High
- CVSS: 7.5 (Important)
- EPSS: 0.0057
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 23, 2026
- Weakness: Integer Overflow or Wraparound
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-6668

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | pgbouncer Debian 14 | 1.26.0-1 | [DEBIAN-CVE-2026-6668](https://patchblox.com/security/data/fix/linux/debian-cve-2026-6668.md) | Oct 4, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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