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PostgreSQLDatabase / datastore

CVE-2026-6637

HIGH · 8.8 CVSS v3.1 Published 2026-05-14
Fix available
A fix is available. Upgrade to 14.23 / 15.18 or later.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Stack buffer overflow in PostgreSQL module "refint" allows an unprivileged database user to execute arbitrary code as the operating system user running the database. A distinct attack is possible if the application declares a user-controlled column as a "refint" cascade primary key and facilitates user-controlled updates to that column. In that case, a SQL injection allows a primary key update value provider to execute arbitrary SQL as the database user performing the primary key update. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-89

User input is woven into a database query, letting an attacker rewrite the query's logic. From there they can read, alter, or destroy data — frequently the entire database. The reliable fix is parameterised queries (prepared statements), so input is always treated as data and never as SQL.

General guidance for the sql injection class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
PostgreSQLDatabase / datastore
Affected:< 14.23>= 15.0, < 15.18>= 16.0, < 16.14>= 17.0, < 17.10>= 18.0, < 18.4

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 14.23 / 15.18 / 16.14 or later
Fixed in 14.2315.1816.14
Vendor patch www.postgresql.org →
Recommended fix High confidence

Upgrade to PostgreSQL 14.23, 15.18, 16.14, 17.10, or 18.4 (or latest stable) depending on your current major version branch

  1. 1. Back up your PostgreSQL database(s) using pg_dump or pg_basebackup before upgrading.
  2. 2. Plan your upgrade path based on your current major version. If currently on PostgreSQL 14.x, upgrade to 14.23. If on 15.x, upgrade to 15.18. If on 16.x, upgrade to 16.14. If on 17.x, upgrade to 17.10. Consider upgrading to the latest stable release (18.4 or the latest 18.x) if migrating to a newer major version.
  3. 3. Stop the PostgreSQL service gracefully (pg_ctl stop or systemctl stop postgresql).
  4. 4. Install the patched PostgreSQL packages from your distribution's package manager or compile from source using the fixed version tarball from https://www.postgresql.org/download/.
  5. 5. Start the PostgreSQL service and verify the version with: SELECT version();
  6. 6. Run ANALYZE on all databases to update statistics after the upgrade.
  7. 7. Test application functionality to ensure compatibility with the upgraded PostgreSQL version.
Caveat Major version upgrades may require schema dumps and restores; review PostgreSQL release notes for breaking changes between versions

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,950. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-6637 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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