Sustained denial of service via recursive negotiation
Published May 14, 2026 · Updated May 14, 2026
Uncontrolled recursion in PostgreSQL before 18.4, 17.10, 16.14, 15.18, and 14.23 allows attackers to sustain a service interruption. The core server recursively processes startup packets when a client alternates rejected SSL and GSS encryption requests, eventually crashing each connected backend. Access to an AF_UNIX socket is sufficient; TCP access is sufficient only when both SSL and GSS are disabled.
Summary
What happened
Uncontrolled recursion in PostgreSQL before 18.4, 17.10, 16.14, 15.18, and 14.23 allows attackers to sustain a service interruption. The core server recursively processes startup packets when a client alternates rejected SSL and GSS encryption requests, eventually crashing each connected backend. Access to an AF_UNIX socket is sufficient; TCP access is sufficient only when both SSL and GSS are disabled.
The record
- CVE
- CVE-2026-6479
- Published
- May 14, 2026
- Updated
- May 14, 2026
- Vendor
- PostgreSQL Global Development Group
- Product
- PostgreSQL
- Classifications
- CWE-674, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 14, 2026CVE publishedPublication date reported by the CVE source.
- May 14, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <14.23
- Affected versionversion=15 <15.18
- Affected versionversion=16 <16.14
- Affected versionversion=17 <17.10
- Affected versionversion=18 <18.4
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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