All errata/c10f2/ALT-PU-2026-18523-2
ALT-PU-2026-18523-2

Package update pgbouncer in branch c10f2

Version1.26.1-alt1
Published2026-10-15
Max severityHIGH
Severity:

Closed issues (3)

CVE-2026-107348
MEDIUM5.9

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.

Published: 2026-10-14Modified: 2026-10-15
CVSS 3.xMEDIUM 5.9
CVSS:3.x/CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CVE-2026-107349
HIGH7.5

An infinite loop in PgBouncer 1.20.0 through 1.26.0 allows an unauthenticated remote attacker to cause a denial of service. A StartupMessage whose options parameter contains an empty parameter name, such as "-c=", makes the ignore_startup_parameters list lookup loop forever. Because PgBouncer serves all clients from a single process, this saturates a CPU core and makes PgBouncer unresponsive to all clients until the process is restarted.

Published: 2026-10-14Modified: 2026-10-15
CVSS 3.xHIGH 7.5
CVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVE-2026-107350
HIGH8.8

Improper authentication in PgBouncer 1.17.0 through 1.26.0 allows a remote attacker who knows the password of a user listed in auth_file to log in as any other user that authenticates using SCRAM, including PgBouncer admin users and backend superusers. A second StartupMessage sent during SCRAM authentication against a non-existent database is not rejected and switches the user being logged in as, while the SCRAM exchange is still verified against the keys of the first user.

Published: 2026-10-14Modified: 2026-10-16
CVSS 3.xHIGH 8.8
CVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H