CVE-2016-5423

CVE-2016-5423 is a high-severity vulnerability in Postgresql with a CVSS 3.x base score of 8.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.

Key facts

• Severity: High (CVSS 3.x base score 8.3)
• CVSS v2: 6.5
• EPSS exploit prediction: 6% (92nd percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-476
• Affected product: Postgresql
• Published: 2016-12-09
• Last modified: 2026-06-17

Description

PostgreSQL before 9.1.23, 9.2.x before 9.2.18, 9.3.x before 9.3.14, 9.4.x before 9.4.9, and 9.5.x before 9.5.4 allow remote authenticated users to cause a denial of service (NULL pointer dereference and server crash), obtain sensitive memory information, or possibly execute arbitrary code via (1) a CASE expression within the test value subexpression of another CASE or (2) inlining of an SQL function that implements the equality operator used for a CASE expression involving values of different types.

Frequently asked questions

What is CVE-2016-5423?

PostgreSQL before 9.1.23, 9.2.x before 9.2.18, 9.3.x before 9.3.14, 9.4.x before 9.4.9, and 9.5.x before 9.5.4 allow remote authenticated users to cause a denial of service (NULL pointer dereference and server crash), obtain sensitive memory information, or possibly execute arbitrary code via (1) a CASE expression within the test value subexpression of another CASE or (2) inlining of an SQL function that implements the equality operator used for a CASE expression involving values of different types.

How severe is CVE-2016-5423?

CVE-2016-5423 has a CVSS 3.x base score of 8.3, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability high.

Is CVE-2016-5423 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (92nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-5423?

CVE-2016-5423 primarily affects Postgresql. In total, 47 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-5423?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2016-5423 published?

CVE-2016-5423 was published on 2016-12-09 and last updated on 2026-06-17.

References

• http://rhn.redhat.com/errata/RHSA-2016-1781.html
• http://rhn.redhat.com/errata/RHSA-2016-1820.html
• http://rhn.redhat.com/errata/RHSA-2016-1821.html
• http://rhn.redhat.com/errata/RHSA-2016-2606.html
• http://www.debian.org/security/2016/dsa-3646
• http://www.securityfocus.com/bid/92433
• http://www.securitytracker.com/id/1036617
• https://access.redhat.com/errata/RHSA-2017:2425
• https://bugzilla.redhat.com/show_bug.cgi?id=1364001
• https://security.gentoo.org/glsa/201701-33
• https://www.postgresql.org/about/news/1688/
• https://www.postgresql.org/docs/current/static/release-9-1-23.html
• https://www.postgresql.org/docs/current/static/release-9-2-18.html
• https://www.postgresql.org/docs/current/static/release-9-3-14.html
• https://www.postgresql.org/docs/current/static/release-9-4-9.html
• https://www.postgresql.org/docs/current/static/release-9-5-4.html

Affected products (47)

• cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:*:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.2:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.2.1:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.2.2:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.2.3:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.2.4:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.2.5:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.2.6:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.2.7:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.2.8:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.2.9:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.2.10:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.2.11:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.2.12:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.2.13:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.2.14:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.2.15:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.2.16:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.2.17:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.3:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.3.1:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.3.2:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.3.3:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.3.4:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.3.5:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.3.6:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.3.7:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.3.8:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.3.9:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.3.10:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.3.11:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.3.12:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.3.13:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.4:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.4.1:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.4.2:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.4.3:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.4.4:*:*:*:*:*:*:*
• cpe:2.3:a:postgresql:postgresql:9.4.5:*:*:*:*:*:*:*

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