Quick answers
- Is CVE-2026-33816 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-33816 being exploited in the wild.
- How severe is CVE-2026-33816?
- 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; Jack Christensen Pgx < 5.9.0.
- Is there a fix for CVE-2026-33816?
- 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-2026-33816 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-33816?
- Check whether you run github.com/jackc/pgx/v5 (Go) or Jack Christensen Pgx 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
go get github.com/jackc/pgx/v5@v5.9.0
Technical details
A memory-safety vulnerability exists in the pgproto3 component of the jackc/pgx/v5 library. The flaw is located within the Backend.Receive and FunctionCall.Decode functions, which are responsible for parsing PostgreSQL wire protocol messages. A remote, unauthenticated attacker can exploit this by sending specially crafted network packets to an application using the library, potentially leading to arbitrary code execution or a denial-of-service (DoS) condition. The issue is addressed in version 5.9.0.
Affected products
- jackc pgx/v5 < 5.9.0
Identifiers
- CVE-2026-33816
- GHSA-9jj7-4m8r-rfcm
- GO-2026-4772
Timeline
- 2026-04-07: disclosed
- 2026-04-07: advisory
- 2026-05-21: other: NIST analysis modified