# CVE-2026-33815: Jackc pgx memory-safety vulnerability in pgproto3

Source: https://junglewise.ai/threats/cve-2026-33815-jackc-pgx-memory-safety-vulnerability-in-pgproto3  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-07. Updated: 2026-06-26  
License: CC BY 4.0 with a link back

CVE-2026-33815 · Severity: critical · CVSS 9.8 · Published 2026-04-07

pgx is a widely used software library that allows Go applications to communicate with PostgreSQL databases. A critical security flaw has been identified that could allow an attacker to interfere with the application's memory. This could lead to unauthorized access to sensitive data, system crashes, or the ability for an attacker to take control of the application.

Technologies: [github.com/jackc/pgx/v5 (Go)](https://junglewise.ai/threats/technologies/github-com-jackc-pgx-v5), [Jack Christensen Pgx](https://junglewise.ai/threats/technologies/pgx). Vendors: [Go](https://junglewise.ai/threats/vendors/go), [Jack Christensen](https://junglewise.ai/threats/vendors/jack-christensen).

## Quick answers

**Is CVE-2026-33815 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-33815 being exploited in the wild.

**How severe is CVE-2026-33815?** Critical severity, with a CVSS score of 9.8, published 7 April 2026.

**Which products and versions are affected?** github.com/jackc/pgx/v5 (Go) < 5.9.0, SEMVER:introduced=0,fixed=5.9.0; github.com/jackc/pgx/v5/pgproto3 (Go) < 5.9.0; Jack Christensen Pgproto3 < 5.9.0; Jack Christensen Pgx < 5.9.0, before v5.9.0.

**Is there a fix for CVE-2026-33815?** Yes. github.com/jackc/pgx/v5 (Go): upgrade to 5.9.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-33815 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-33815?** Check whether you run github.com/jackc/pgx/v5 (Go), github.com/jackc/pgx/v5/pgproto3 (Go), Jack Christensen Pgproto3 or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/jackc/pgx/v5 (Go): upgrade to 5.9.0 or later

  ```sh
  go get github.com/jackc/pgx/v5@v5.9.0
  ```


## Technical details

A memory-safety vulnerability exists in the pgx toolkit (github.com/jackc/pgx/v5) prior to version 5.9.0. The flaw allows for potential memory corruption or unauthorized memory access via the network without requiring authentication or user interaction. While specific CWE details are not provided in the advisory, the CVSS score of 9.8 and the 'memory-safety' classification suggest a high risk of remote code execution (RCE) or information disclosure. The issue is addressed in version 5.9.0.

## Affected products

- jackc pgx < 5.9.0

## Identifiers

- CVE-2026-33815
- GHSA-xgrm-4fwx-7qm8
- GO-2026-4771

## Timeline

- 2026-04-07: disclosed
- 2026-04-07: advisory
- 2026-04-10: other: GitHub reviewed

## References

- [https://api.github.com/users/mitar](https://api.github.com/users/mitar)
- [https://github.com/mitar](https://github.com/mitar)
- [https://api.github.com/users/mitar/gists%7B/gist_id%7D](https://api.github.com/users/mitar/gists%7B/gist_id%7D)
- [https://api.github.com/users/mitar/repos](https://api.github.com/users/mitar/repos)
- [https://avatars.githubusercontent.com/u/585279?v=4](https://avatars.githubusercontent.com/u/585279?v=4)
- [https://api.github.com/users/mitar/events%7B/privacy%7D](https://api.github.com/users/mitar/events%7B/privacy%7D)

## Related threats

- [jackc pgx SQL injection in simple protocol sanitizer](https://junglewise.ai/threats/cve-2026-41889-jackc-pgx-sql-injection-in-simple-protocol-sanitizer)
- [jackc pgx memory safety vulnerability in pgproto3](https://junglewise.ai/threats/cve-2026-33816-jackc-pgx-memory-safety-vulnerability-in-pgproto3)
- [Jackc pgproto3 denial of service in DataRow.Decode](https://junglewise.ai/threats/cve-2026-32286-jackc-pgproto3-denial-of-service-in-datarow-decode)
- [Panic in Pipeline when PgConn is busy or closed in github.com/jackc/pgx](https://junglewise.ai/threats/panic-in-pipeline-when-pgconn-is-busy-or-closed-in-github-com-jackc-pgx-b06ba063)
- [GO-2024-2567 - Panic in Pipeline when PgConn is busy or closed in github.com/jackc/pgx](https://junglewise.ai/threats/go-2024-2567-panic-in-pipeline-when-pgconn-is-busy-or-closed-in-github-8819cd3b)