Integer overflow in the message buffer growth logic ...
Moderate severity
Unreviewed
Published
Oct 14, 2026
to the GitHub Advisory Database
•
Updated Oct 14, 2026
Description
Published by the National Vulnerability Database
Oct 14, 2026
Published to the GitHub Advisory Database
Oct 14, 2026
Last updated
Oct 14, 2026
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.
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