What is CVE-2026-16723?

CVE-2026-16723 is a critical-severity vulnerability in Alibaba Fastjson, classified under Improper Input Validation. CVSS score: 9.0/10. Published 2026-07-23.

How severe is CVE-2026-16723?

Critical severity. CVSS v3 base score is 9.0 out of 10.

Deserialization in Alibaba Fastjson

CVE-2026-16723

A remote code execution (RCE) vulnerability exists in fastjson 1.2.68 through 1.2.83. This vulnerability is exploitable under fastjson's stock default configuration — no AutoType enablement required, no classpath gadget required.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

CVSS v3 metric

CVSS v3 base score 9.0 (Critical). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H.

Affected products

Alibaba Fastjson — versions 1.2.68

Weakness classification (CWE)

CWE-20 — Improper Input Validation
CWE-502 — Deserialization of Untrusted Data

References

alibaba-cna@list.alibaba-inc.com (vendor-advisory, mitigation)

Frequently asked questions

What is CVE-2026-16723?: CVE-2026-16723 is a critical-severity vulnerability in Alibaba Fastjson, classified under Improper Input Validation. CVSS score: 9.0/10. Published 2026-07-23.
How severe is CVE-2026-16723?: Critical severity. CVSS v3 base score is 9.0 out of 10.