What is CVE-2023-39321?

CVE-2023-39321 is a high-severity vulnerability in Golang Go, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2023-09-08.

How severe is CVE-2023-39321?

High severity. CVSS v3 base score is 7.5 out of 10.

Is CVE-2023-39321 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Resource exhaustion in Golang Go

CVE-2023-39321

Processing an incomplete post-handshake message for a QUIC connection can cause a panic.

Vulnerability class: DoS (Denial of Service)

Published 2023-09-08 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.014 (70.5th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 71st percentile — 70.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.011 · newest: 0.014 · change: +0.002

Affected products

Golang Go
Go Standard Library Crypto/tls — versions 1.21.0-0

Weakness classification (CWE)

CWE-400 — Uncontrolled Resource Consumption

Public proof-of-concept exploits

ARPSyndicate/cve-scores

References

go.dev/issue/62266 (Issue Tracking)
go.dev/cl/523039 (Patch)
groups.google.com/g/golang-dev/c/2C5vbR-UNkI/m/L1hdrPhfBAAJ (Release Notes)
pkg.go.dev/vuln/GO-2023-2044 (Vendor Advisory)
security.netapp.com/advisory/ntap-20231020-0004/ (Third Party Advisory)
security.gentoo.org/glsa/202311-09

Frequently asked questions

What is CVE-2023-39321?: CVE-2023-39321 is a high-severity vulnerability in Golang Go, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2023-09-08.
How severe is CVE-2023-39321?: High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2023-39321 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.