Critical Vulnerability in PgBouncer Affects Remote Authentication
CVE-2026-19888

7.5HIGH

Key Information:

Vendor

PgBouncer

Status
Pgbouncer
Vendor
CVE Published:
23 September 2026

What is CVE-2026-19888?

The vulnerability arises from inadequate validation of mandatory attributes in the SCRAM client-final-message parser within PgBouncer up to version 1.25.2. This flaw allows an unauthenticated remote attacker to exploit the parser by sending a malformed message. The parser may incorrectly report success while failing to set a required value, subsequently leading to a NULL pointer dereference. As a result, the PgBouncer process crashes, which affects all pooled connections, disrupting service for every client without requiring any valid credentials.

Affected Version(s)

PgBouncer 0 <= 1.25.2

References

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

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Thanks to @mble for finding and reporting this issue.
Independently reported by @thesecguy45.
Independently reported by @umutbasal.
Independently reported by @jackds-security.
Independently reported by @palak-paneer.
Independently reported by @shakirov-vm.
.