CVE-2026-14672: PostgreSQL observable response discrepancy with non-default scram_iterations provides user existence oracle
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 scramiterations count, because the authentication challenge for a nonexistent user reports the default scramiterations. Within major versions 16-18, minor versions before PostgreSQL 18.6, 17.11, and 16.15 are affected. Versions before PostgreSQL 16 are unaffected.
Other sources
PostgreSQL observable response discrepancy with non-default scramiterations provides user existence oracle
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 16.15-1
Event History
Frequently Asked Questions
What is the severity of CVE-2026-14672?
The severity of CVE-2026-14672 is medium, with a score of 5.3.
What does CVE-2026-14672 exploit in PostgreSQL?
CVE-2026-14672 exploits an observable response discrepancy in PostgreSQL SCRAM authentication.
How can an attacker use CVE-2026-14672?
An attacker can use CVE-2026-14672 to determine the existence of a user by observing the SCRAM iteration count during authentication.
What version of PostgreSQL is affected by CVE-2026-14672?
CVE-2026-14672 affects PostgreSQL installations that utilize SCRAM authentication with non-default scram_iterations settings.
How can I mitigate CVE-2026-14672?
To mitigate CVE-2026-14672, consider configuring PostgreSQL to use default scram_iterations or implementing additional rate limiting on authentication attempts.