CVE-2026-19888: NULL pointer dereference in SCRAM client-final-message parsing in PgBouncer

Severity: high (CVSS 7.5 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: 2026-09-23 · updated 2026-09-23
Weakness: CWE-476

Description

Missing validation of a mandatory attribute in the SCRAM client-final-message parser in PgBouncer through 1.25.2 allows an unauthenticated remote attacker to crash the process. A malformed message can make the parser report success while leaving a required value unset, which is then dereferenced as a NULL pointer. The crash occurs before any credential is verified, so no valid account is required. Because PgBouncer serves all clients from a single process, this terminates every pooled connection.

Affected products

PgBouncer: through 1.25.2

References

https://www.pgbouncer.org/changelog.html

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