Critical Security Vulnerability in PostgreSQL 18: Multiple CVEs Addressed
Summary
RLSA-2026:27742: Important: postgresql18 security update. Affects postgresql18 versions < 0:18.4-1.el10_2. Fixed in 0:18.4-1.el10_2. How to fix ↓
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Background
PostgreSQL is an advanced Object-Relational Database Management System (DBMS) known for its robustness and feature-rich capabilities. It supports various data types and offers powerful querying capabilities, making it a popular choice for developers and enterprises. However, recent vulnerabilities have been identified in version 18, which could potentially compromise the security of systems utilizing this database.
Vulnerability Detail
The vulnerabilities in PostgreSQL 18 stem from multiple sources, including an operating system account hijack via symlink in pg_basebackup and pg_rewind (CVE-2026-6475), a buffer overflow that allows server superusers to overwrite client stack memory (CVE-2026-6477), a covert timing channel in MD5 password comparison that could lead to credential recovery (CVE-2026-6478), and an integer overflow that can cause undersized allocation and out-of-bounds write (CVE-2026-6473). These vulnerabilities could lead to unauthorized access, data corruption, and potential system compromise.
How To Fix
Minimum fixed version
0:18.4-1.el10_2
This is the first release that contains the fix.
sudo dnf update postgresql18Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary measure, consider restricting access to the PostgreSQL server and implementing additional monitoring to detect any unauthorized access attempts. Regularly review user permissions and ensure that only trusted accounts have access to critical database functions.
Conclusion
The identified vulnerabilities in PostgreSQL 18 pose significant risks to database security. It is crucial for users to update to the latest patched version to mitigate these risks. Implementing temporary workarounds can provide additional protection while updates are being applied.
See every vulnerability recorded for postgresql18 →
FAQ
The main vulnerabilities include account hijacking via symlink, buffer overflow, credential recovery via timing channels, and integer overflow leading to out-of-bounds writes.
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The CVSS score for these vulnerabilities is 8.8, indicating a critical level of severity.
If immediate updates are not possible, implement strict access controls and monitor for any suspicious activity as a temporary workaround.
The Rocky Enterprise Software Foundation and Red Hat are credited for addressing these vulnerabilities through the security update.
References
Related vulnerabilities
Recent vulnerabilities recorded for postgresql18.
