Authenticated row-security bypass via MERGE
Published Aug 11, 2023 · Updated Nov 21, 2025
PostgreSQL 15 MERGE row security flaw allows remote authenticated users to store rows blocked by UPDATE or SELECT policies via a crafted MERGE. The MERGE executor applies INSERT checks to UPDATE rows and omits required SELECT-policy checks, allowing rows forbidden by the table's row-level security rules to be stored. Exploitation requires a database account able to issue MERGE against a table using CREATE POLICY; consequences are application-dependent and primarily affect data integrity.
Summary
What happened
PostgreSQL 15 MERGE row security flaw allows remote authenticated users to store rows blocked by UPDATE or SELECT policies via a crafted MERGE. The MERGE executor applies INSERT checks to UPDATE rows and omits required SELECT-policy checks, allowing rows forbidden by the table's row-level security rules to be stored. Exploitation requires a database account able to issue MERGE against a table using CREATE POLICY; consequences are application-dependent and primarily affect data integrity.
The record
- CVE
- CVE-2023-39418
- Published
- Aug 11, 2023
- Updated
- Nov 21, 2025
- Vendor
- Red Hat
- Product
- Red Hat Enterprise Linux 8
- Classifications
- T1565.001
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 11, 2023CVE publishedPublication date reported by the CVE source.
- Nov 21, 2025Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
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Technologies
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