Integer overflow in Pgbouncer
CVE-2026-107348
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.
Vulnerability class: Integer Overflow
Published .
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Pgbouncer
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-107348?
- CVE-2026-107348 is a medium-severity vulnerability in Pgbouncer, classified under Integer Overflow or Wraparound. CVSS score: 5.9/10. Published 2026-10-14.
- How severe is CVE-2026-107348?
- Medium severity. CVSS v3 base score is 5.9 out of 10.