CVE-2026-16723: A remote code execution (RCE) vulnerability exists in fastjson 1.2.68 through 1.2.83

Q: How do I fix CVE-2026-16723?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Q: Is CVE-2026-16723 being exploited?

CVE-2026-16723 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-16723 affect?

CVE-2026-16723 affects affected software. Severity is critical (CVSS 9.0). 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.

Q: How urgent is CVE-2026-16723?

Priority 49/100. Critical severity; Remotely exploitable, no login, no user action

This month

CRITICAL 9.0REMOTE

CVE-2026-16723 is a critical-severity flaw (CVSS 9.0) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.0 (Critical)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 49%)
CISA exploited list	No
Weakness	CWE-20, CWE-502
Published	2026-07-23
Last modified	2026-10-24

Publisher (CNA): Alibaba, Inc.

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-07-23 09:16 UTCPublished CVE record published
2026-10-24 13:10 UTCUpdated Record last modified

Exact fixes by distribution

Maven · com.alibaba:fastjson · NO FIX YET · vulnerable: >= 1.2.68, <= 1.2.83 · source

Fedora 46 · gnome-shell-extension-tiling-assistant · FIXED · 56-1.fc46 · FEDORA-2026-ebf66a5321 · source

sudo dnf upgrade --advisory=FEDORA-2026-ebf66a5321

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: dinosn/fastjson-jsontype-rce-lab (207 stars)
GitHub PoC: learner330/fastjson-cve-2026-16723 (5 stars)
GitHub PoC: why-success/fastjson-rce-lab (4 stars)

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-16723?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2026-16723 being exploited?

CVE-2026-16723 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-16723 affect?

CVE-2026-16723 affects affected software. Severity is critical (CVSS 9.0). 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.

How urgent is CVE-2026-16723?

Priority 49/100. Critical severity; Remotely exploitable, no login, no user action

References

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