CVE-2026-107348 Integer overflow causes an infinite loop in message buffer growth in PgBouncer
Remote attackers can cause denial of service via integer overflow in PgBouncer when max_packet_size is set above 2GB, stalling all connections.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-107348?
CVE-2026-107348 is a medium-severity vulnerability in PgBouncer, published on 14 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Integer overflow in the message buffer growth logic (mbuf_make_room) in PgBouncer 1.21.0 through 1.26.0 allows a remote attacker to cause a denial of service when max_packet_size is configured above 2147483648. A packet header declaring a length above 2^31 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 restarted. Since 1.23.0 the overflow is reachable before authentication with a five-byte packet header.
Which versions are affected by CVE-2026-107348?
1 open source package ship an affected version, including pgbouncer.
| Package | Affected | Fixed in |
|---|---|---|
pgbouncer Bitnami | From 1.21.0 | 1.26.1 |
How do I fix CVE-2026-107348?
Upgrade pgbouncer to 1.26.1 or later.
Is CVE-2026-107348 being exploited?
There is no known exploitation of CVE-2026-107348 in the wild and no public exploit code.
Sources
Also known as AZL-108195, BIT-pgbouncer-2026-107348, DEBIAN-CVE-2026-107348, ECHO-5e11-e26f-413f, GHSA-982p-g5h4-w372, UBUNTU-CVE-2026-107348.