Bug 2539545 (CVE-2026-19888)

Summary: CVE-2026-19888 pgbouncer: PgBouncer: Denial of Service via malformed SCRAM client-final-message
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in PgBouncer. Missing validation of a mandatory attribute in the SCRAM client-final-message parser allows an unauthenticated remote attacker to crash the process. By sending a malformed message, the parser can report success while a required value remains unset, leading to a NULL pointer dereference. This crash occurs before any credentials are verified and terminates all pooled connections, resulting in a Denial of Service.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2539630, 2539631    
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Description OSIDB Bzimport 2026-09-23 17:03:10 UTC
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.