What’s Vulnerable › Vulnerabilities
CVE-2026-107348: Integer overflow causes an infinite loop in message buffer growth in PgBouncer
- Severity: medium (CVSS 5.9 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-10-14 · updated 2026-10-16
- Weakness: CWE-190
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.
Affected products
- PgBouncer: from 1.21.0 before 1.26.1 — fixed in 1.26.1
How to fix
Upgrade to a fixed version: PgBouncer 1.26.1. Check the vendor advisory for mitigations.
References
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