CVE-2026-14672 PUBLISHED

PostgreSQL observable response discrepancy with non-default scram_iterations provides user existence oracle

Assigner: PostgreSQL
Reserved: 03.07.2026 Published: 13.08.2026 Updated: 13.08.2026

Observable response discrepancy in PostgreSQL SCRAM authentication allows an unauthenticated user to test the existence of a user via observing the SCRAM iteration count. This requires the probed user to have a non-default scram_iterations count, because the authentication challenge for a nonexistent user reports the default scram_iterations. Within major versions 16-18, minor versions before PostgreSQL 18.5, 17.11, and 16.15 are affected. Versions before PostgreSQL 16 are unaffected.

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CVSS Score: 5.3

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	Low
Privileges Required	None	Integrity Impact	None
User Interaction	None	Availability Impact	None

CVSS 3.1

Product Status

Vendor	n/a
Product	PostgreSQL
Versions	Default: unaffected affected from 18 to 18.5 (excl.) affected from 17 to 17.11 (excl.) affected from 16 to 16.15 (excl.)

Affected Configurations

user's SCRAM verifier has non-default iteration count

Credits

The PostgreSQL project thanks Radim Marek for reporting this problem.

References

https://www.postgresql.org/support/security/CVE-2026-14672/

Problem Types

Observable Response Discrepancy CWE