CVE-2026-14673 is a vulnerability in PostgreSQL's amcheck extension where the function does not clear an untrusted search path. A grantee with EXECUTE privilege on the amcheck function can set a malicious search path before calling it, resulting in arbitrary function execution as the owners of expression indexes that depend on the search path. This affects PostgreSQL versions 14.0 up to but not including 14.24, 15.0 up to but not including 15.19, 16.0 up to but not including 16.15, and 18.0 up to but not including 18.5. PostgreSQL 17 is unaffected.

An attacker with EXECUTE privilege on the amcheck function can exploit this vulnerability to execute arbitrary functions with the privileges of the owners of expression indexes. This could lead to unauthorized actions within the database context. The severity is rated low.

A patch is available for this vulnerability. Users should upgrade affected PostgreSQL versions to 14.24 or later, 15.19 or later, 16.15 or later, or 18.5 or later to remediate the issue. No additional mitigations are specified.