Critical Buffer Overflow Vulnerability in libpq Package: PostgreSQL Client Library
Summary
ALSA-2026:44391: Important: libpq security update. Affects libpq versions < 16.14-1.el10_2. Fixed in 16.14-1.el10_2. How to fix ↓
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Background
The libpq package is the PostgreSQL client library that enables client applications to connect to PostgreSQL servers. It is a crucial component for database interactions, providing functionalities such as executing SQL commands and managing database connections. The libpq-devel package includes development files for building applications that use the libpq library. This vulnerability affects both packages, making it essential for users to address it promptly to maintain application security.
Vulnerability Detail
The vulnerability identified as CVE-2026-6477 is a buffer overflow issue that allows a server superuser to overwrite client stack memory. This can lead to unauthorized access, data corruption, or even remote code execution, posing a significant risk to applications that rely on the libpq library for database connectivity. The flaw arises from improper handling of data, which can be exploited if an attacker has superuser access to the PostgreSQL server.
How To Fix
Minimum fixed version
16.14-1.el10_2
This is the first release that contains the fix.
sudo dnf update libpqTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, consider restricting superuser access on the PostgreSQL server to mitigate the risk of exploitation until the packages can be updated. Additionally, review and limit the permissions of users who can connect to the database.
Conclusion
The libpq package is essential for PostgreSQL client-server interactions, but the identified buffer overflow vulnerability (CVE-2026-6477) poses serious security risks. Users are urged to update to the patched version to safeguard their applications. Temporary workarounds can help mitigate risks until updates are applied.
See every vulnerability recorded for libpq →
FAQ
CVE-2026-6477 is a buffer overflow vulnerability in the libpq package that allows a server superuser to overwrite client stack memory.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without needing to sign up.
Exploitation of this vulnerability can lead to unauthorized access, data corruption, or remote code execution, posing a significant risk to applications.
You can update the libpq and libpq-devel packages by running 'sudo dnf update libpq libpq-devel' in your terminal.
Yes, you can restrict superuser access on the PostgreSQL server and review user permissions to mitigate the risk until the packages are updated.
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