Use of Inherently Dangerous Function Affecting libpq package, versions [14.2,]
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-CONAN-LIBPQ-16691381
- published14 May 2026
- disclosed14 May 2026
- creditYu Kunpeng, Martin Heistermann
Introduced: 14 May 2026
NewCVE-2026-6477 (opens in a new tab)How to fix?
A fix was pushed into the master branch but not yet published.
Overview
Affected versions of this package are vulnerable to Use of Inherently Dangerous Function via the PQfn function when called with result_is_int=0 in the lo_export, lo_read, lo_lseek64, and lo_tell64 functions. An attacker can overwrite client stack memory with arbitrary data by sending a specially crafted, large response from the server superuser. This can lead to compromise of client applications such as psql or pg_dump when they interact with a malicious server superuser.
Workaround
This vulnerability can be mitigated by using PQexecPrepared() instead of PQfn(..., result_is_int=0, ...) or its lo_* wrappers.