Critical Security Update for PostgreSQL: Addressing Multiple Vulnerabilities
Summary
ALSA-2026:26204: Important: postgresql:18 security update. Affects pg_repack versions < 1.5.3-1.module_el9.8.0+234+5456f35d. Fixed in 1.5.3-1.module_el9.8.0+234+5456f35d. How to fix ↓
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Background
PostgreSQL is an advanced object-relational database management system (DBMS) known for its robustness, extensibility, and support for complex queries. It is widely used in various applications for managing data efficiently. However, recent vulnerabilities have been identified that could compromise the security of PostgreSQL installations, particularly affecting versions prior to the patched releases.
Vulnerability Detail
The vulnerabilities identified in PostgreSQL include an operating system account hijack via symlink in pg_basebackup and pg_rewind (CVE-2026-6475), a buffer overflow that allows a server superuser to overwrite client stack memory (CVE-2026-6477), credential recovery via a covert timing channel in MD5 password comparison (CVE-2026-6478), and an integer overflow that can lead to an undersized allocation and an out-of-bounds write (CVE-2026-6473). These vulnerabilities can lead to unauthorized access, data corruption, and potential system compromise.
How To Fix
Minimum fixed version
1.5.3-1.module_el9.8.0+234+5456f35d
This is the first release that contains the fix.
sudo dnf update pg_repackTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary measure, users can restrict access to the PostgreSQL server and limit the use of the affected features until the updates are applied. Additionally, consider using alternative authentication methods that do not rely on MD5 password comparison.
Conclusion
In summary, the recent vulnerabilities in PostgreSQL pose serious security risks that can lead to unauthorized access and data corruption. It is crucial for users to update their installations to the patched versions as soon as possible to mitigate these risks.
See every vulnerability recorded for pg_repack →
FAQ
The main vulnerabilities include account hijacking via symlink, buffer overflow, credential recovery through timing channels, and integer overflow leading to out-of-bounds writes.
You can use Vulert's playground at Vulert Scanner to check if your application is affected by these vulnerabilities without requiring any signup.
If immediate updates are not possible, restrict access to the PostgreSQL server and limit the use of affected features as a temporary workaround.
While specific exploits may not be publicly available, the vulnerabilities pose significant risks, and it is advisable to apply the patches as soon as possible.
For more details, refer to the CVE pages associated with each vulnerability: CVE-2026-6473, CVE-2026-6475, CVE-2026-6477, and CVE-2026-6478.
Related vulnerabilities
Recent vulnerabilities recorded for pg_repack.
