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CVE-2026-6473 Postgresql CVE debrief

CVE-2026-6473 is a high-severity PostgreSQL server vulnerability caused by integer wraparound in multiple server features. An unprivileged database user may be able to trigger an undersized allocation followed by an out-of-bounds write. Depending on the affected path and deployment, this can lead to arbitrary code execution as the operating system user running PostgreSQL. The NVD record also notes that in applications passing gigabyte-scale user inputs to the relevant database functions, the application input provider may cause a segmentation fault. Affected versions are those before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23.

Vendor
Postgresql
Product
Unknown
CVSS
HIGH 8.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-14
Original CVE updated
2026-08-25
Advisory published
2026-05-14
Advisory updated
2026-08-25

Who should care

PostgreSQL administrators, managed database operators, application teams that expose PostgreSQL functions to large user-controlled inputs, and security teams responsible for database patching and version hygiene.

Technical summary

The NVD describes an integer wraparound issue (CWE-190) in multiple PostgreSQL server features. The flaw can cause the server to compute an allocation that is too small, then perform an out-of-bounds write. The vulnerability is reachable by an unprivileged database user and is rated CVSS 3.1 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H). Vulnerable version ranges are all releases before 14.23, 15.18, 16.14, 17.10, and 18.4.

Defensive priority

High. This is a remotely reachable database-server flaw with low attack complexity and potential for code execution, so patching should be prioritized quickly across all exposed PostgreSQL instances.

Recommended defensive actions

  • Upgrade PostgreSQL to a fixed release: 18.4, 17.10, 16.14, 15.18, or 14.23, or later.
  • Inventory all PostgreSQL deployments, including embedded, replicated, and managed-service instances, and verify exact server versions.
  • Review any application code that passes very large user-controlled inputs into PostgreSQL functions and reduce or validate input sizes where feasible.
  • Restrict who can create or execute database functions and monitor for unusual database-user activity while patching is in progress.
  • Consult the PostgreSQL security advisory for CVE-2026-6473 and apply vendor guidance specific to your deployment.

Evidence notes

Grounded in the supplied NVD record and its linked PostgreSQL security advisory reference. The description states integer wraparound can cause undersized allocation and out-of-bounds write, potentially enabling arbitrary code execution as the OS user running PostgreSQL. NVD marks the issue as CWE-190 and rates it CVSS 3.1 8.8. Version bounds are explicitly listed in the supplied CPE criteria and description.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-6473 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-6473

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-6473 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-6473

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Mitigation or vendor reference

    Unverified legacy reference

    URL: https://www.postgresql.org/support/security/CVE-2026-6473/

    f86ef6dc-4d3a-42ad-8f28-e6d5547a5007 - Patch, Vendor Advisory

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.